my stepdad recently bought a 74 F100 w/ a straight 6 in it. i've driven it and am horribly unimpressed w/ it. unfortunately, because of smog laws, i can't put anything outrageous in it... yet. what i was wondering is this: what engines came in the F100 stock, and does anyone have one of those (bigger v8's) for sale in good condition at a reasonable price?

 

Which I-6 do you have? I'm not sure about '74, but Ford made 2 I-6 engines: the 240 and the 300.

Regardless of which you have, and which state you live in, there are some smog-legal improvements you can make which can improve the performance of your stepdad's truck. Rebuild his engine with a slightly beefier cam, improved intake and exhaust manifolds, free-flowing exhaust, hotter ignition system, etc.

The problem with installing a V-8 is that you need to change so many things that it may not be worth it (it would be cheaper and easier to find a V-8 truck and spend your money improving it).

Some of the things you need to change are the motor perches and mounts, engine and trans linkage, drive line, exhaust system, etc. If you're serious about converting to a V-8 it's best to buy a donor truck so you have everything you need for the conversion.

Good luck.

Bruce

 

>The problem with installing a V-8 is
>that you need to change so
>many things....
>engine and trans linkage, drive
>line, exhaust system, etc.

I just finished aN I6 to 351W swap; linkages were pretty straight forward (need to swap to 351 linkages); no change to drive line required; can easily maintain same exhaust if you use factory exhaust manifolds, it's a little harder if you run headers; my biggest problem was the accessories on the front end, you need to find a comparable engine with everything in tact and purchase the entire setup, I tried to piece mine together with after market accessory brackets and it's a pain in the rear!! ...and you need to swap your radiator (trust me on this one!!)

Hope that helps,

Slik

 

You better leave that "Poor old Sixbanger" alone. You'd be doing your FIL a favor too. I had several of the 300 Six's in Truck's and got good service and long life times out of all of them.
The mileage was always 13-15 Mpg. I was always able to run on the Hiway, at speed, pulling my boat's ETC,ETC.
Here in Alaska we use the California Emissions Standard's and you might never get to use a vehicle like that because it's been modified.
You would gain nothing with a change like that. The cost is prohibitive and you need the "donor truck". You would lose some Mpg, and gain a little torque, but you would have to change the Rear end ratio, or the engine will be revving a bit too much.
I also had good luck with a 240,292,312,352,390 and a 460. But overall I liked the Six's the best.
#####

 

The previous owner of my '64 F100 pulled its original 6 cylinder and put in a 302 V8. This yahoo did such a good job that I immediately yanked the 302 back out and I am now in the process of reinstalling the original 262 6 cylinder. His "conversion" tactics have practically destroyed the truck. Fortunately, I should be able to pound the linkages back into shape and get rid of the crappy V8 motor mounts he tried to weld in. Yes, he did change the trans, driveshaft, coupler, etc. to accommodate his V8, and now I will have to change them all back just to get the truck on the road. What a mess!

So, if you can, try to save the 6 cylinder. Unless you're willing to drop a few thousand dollars and do the job right, a V8 swap can easily wreck the truck. A poorly installed V8 will be no more impressive than a good-running I-6 (trust me!). However, if you want, I will give you that 302 for free. Good riddance to it!!

 

Dan, thats a bunch of BS Hooy. You may have bought a botched installation in your truck, but upgrading to a V8 will in no way shape or form wreck a truck, nor devalue it. I could put the 302 in your 64, and if you didn't know that 302s weren't available then, you would think is was a factory install. Unless you punch the 6 out, most all of the 8s can cream it.

John

 

This turned out to be an interesting thread.

I am the original owner of an '81 F-100 with a 300 six and a 4-speed. The original 4-speed was a very light duty trans and had 4th as overdrive. It lasted 120,000 miles and died in 1992. I replaced it with a 5-speed from a '91 F-150 and am very pleased with it. New the truck got 19 MPG on the freeway and 16-17 MPG around town. It now has 230,000 miles on it and gets 17 MPG on the freeway and 15-16 MPG in combined use. Not bad for a truck that cost me $7,500 new. That trans swap and a new catalytic converter at 150,000 mi. are the only major work I've ever done to it.

With that 300 cu six I can do everything I need to do with a light-duty truck, including pulling my 24' travel trailer or filling the bed with 2X4s and plywood from Home Base. I've never considered swaping that motor because I love it. I wish I could put a 2-bbl carb on it, but in California that won't happen. That 1-bbl carb is the limiting factor on HP & torque. During it's life I've never reved that motor over 3,000 RPM.

In early June I bought a '71 F-350 which had its 390 go bad. It's an Explorer and a Camper Special and is a very nice California truck with no rust. The owner started to swap in a 460 & C6 but lost interest & I got the whole thing for $1,300. I have a freshly rebuilt 400M and C6 I'm installing and the conversion has had its share of headaches. If I was replacing that 390 with another FE & C6 I would have been done by June 30. However, all the little things that need to be changed has stretched-out the conversion. I now have the truck running but the brakes were bad (metal to metal in front and leaking in back) so I did the front brakes last weekend and I'll do the rear brakes next weekend. Then I can start on the cosmetics.

What I'm trying to say is that the six bangers have a place and are very dependable trucks that will shoulder their share of the work, but don't confuse them with hot rods. The heavier trucks with big V-8s will do any thing you need them to do, but you pay for this everytime you go to the gas station. Light trucks with small to medium V-8s are the best of both worlds and I will never chastise someone for wanting one.

I got my '71 F-350 because I needed a heavier truck from time to time and it's old enough that I don't need to smog it. I will keep my '81 F-100 for general use and give it to my oldest son when he is ready to drive.

Keep in mind that the 300 six has a 4.00" stroke whereas the 302 has a 3.00" stroke and the 351 has a 3.5" stroke. The 300 six is a slow-turning, torquey truck motor, the 302 is a high reving car motor and the 351 is both. I have a 302 in my '84 Bronco and a 289 in my '68 Mustang GT/CS.

I love these old Fords.

Bruce

 

Bruce I will agree with what you state. I am ok with Dan's first paragraph, it's the second that I have trouble with. If you like the 6 bangers keep em. When Ford had White Motor Co. design the 300 6 they came up with a hell of a good engine, but to say that putting a v8 in a truck will defame it, is just plain BS.

John

 

jowilker,

I do not doubt that you could install the 302 much more professionally than the previous owner of my truck did. I am very happy there are people like you out there who can do the job right. However, let's face it: a lot of people who buy an old 6 cylinder Ford pickup to fix up are "on a budget" and are trying to make it "burn rubber" for cheap. Otherwise, they'd buy a truck that came from the factory with a big V8, then have a performance shop do the rest. But no! Instead, they pull out a perfectly good inline 6 for a junkyard-picked V8 because they think they'll be able to smoke the tires at a traffic light. Chrome rims, rusty wheel wells and the whole bit. Of course, these trucks have about two months left to live at that point. What a waste! If all you are interested in is "creaming" a 6 cylinder with a V8, then I hope I never buy a truck from you. I drive a Ford pickup for a very different reason: because it is useful, dependable and fun. If I wanted V8 power to "cream" people with, I would pick up a Camaro.

Also, I really don't appreciate the "BS hooy" comment. My advice is as valuable as yours, and if you don't agree, I think you could find a more professional way to express yourself. I have enjoyed this message board because it has always been a forum of mutual respect -- so much for that!

 

What's more, if you read my earlier statement about V8s carefully, I did not say that a V8 will defame, devalue or otherwise hurt a truck if properly installed. I think Ford V8s are perfectly fine engines. It is not all that hard to swap from a 6 to an 8. My point is, why would you bother? For the expense of doing it right (which is significant -- no matter what you say), one would usually be better off to sell the 6 cylinder truck and buy one that is already equipped with a V8. You can conceivably break even and your swap is already done! Then, if you want, you can add performance options until your truck is more hot rod than work vehicle. (I totally agree with Bruce's earlier comment regarding the confusion of the two.)

And yes, I have seen dozens of old Fords that have been "devalued" because their owners saw fit to tear out the smooth-running, original six cylinder in favor of more power. Most of these guys don't even tow trailers or haul heavy loads! They just want to mess around. They think they can make it better and often end up making it worse. It is really sad.

So please, if you are going to do it, do it right. Don't install a used engine without hearing it run first or, preferably, rebuilding it. Install fresh motor mounts and tranny mounts. Make sure the driveshaft and rear end can handle the torque of your V8 of choice. Connect and test the gauges before ever turning the "new" engine over. Replace the radiator with one designed for a V8 (new or recored). Install all new hoses and clamps. Install a new clutch, pressure plate, pilot bushing and throwout bearing or, on an automatic, a new converter and transmission cooler lines. Find and install the correct shift linkage, throttle linkage and (if applicable) kickdown linkage. Install the proper exhaust system header pipe(s). Wait, I smell money burning!

Or just jury-rig the whole thing and save a buck. ("Say, my truck really had a lot of power on the way to where it blew up!")

Again, don't get me wrong. For a few hundred or thousand extra dollars, you can do the swap right and enjoy many years of dependable service from your Ford pickup. I have seen a few done properly and they are fine trucks. Their owners are bright, meticulous people who never miss a tooth washer or a torque spec. Of course, they also have a rather large budget for such projects.

 

Dan, You are very much like the president, you just can't remember. 1st of all I tried to attact your statement and not you directly. It is your statement and I quote from number 4 of this thread "a v8 swap can easily wreck the truck" That sir is Hooy plain and simple. "Unless you are willing to drop a few thousand dollars to do the job right" sir is just plain hooy.I have never seen people put 6 bangers in to burn rubber. People bother to swap 6s for 8s to get more power. I glad you have enough, maybe you live in flat country and don't need the extra power of the 8'. That camaro comment exposed you for a Chevy lover after all. Shame on you, for hanging out on a Ford site.

John

 

I'd like to chime in on the hooey.

Anyone who replaces a 300 CI six for a 302 is incurring a lot of expense for a few horsepower and a reduction in torque. Unless you love the lopy idle of a V-8, why go through the hassle? I have a 302 in my '84 Bronco and that little V8 has to work hard to move that Bronco. It'd be cheaper and easier to add a good cam, headers, and a good intake and carb to the 300 to get up to 302 power levels.

Swapping a 390 or 460 into a six cyl truck would give you major improvements, but then you need to start looking at the chassis, brakes, suspension, driveline and rear end to make sure they can handle the increased torque.

Anyone can do a decent conversion, it just takes time and money. The guy I bought my F-350 from was in the process of doing a typical shade-tree conversion that would have caused him headaches later. He was installing a used 460 and C-6 without rebuilding them. He was using the wrong motor mount perches and was trying to "wing-it". Problems with the trans and drive line caused him to hit the wall and lose interest.

The first thing I did was pull his used motor and trans and put them in my garage for a future rebuild and use in another project vehicle (maybe my '67 Mustang fastback I bought 3-years ago without a motor?). The second thing I did was spend a weekend scraping 28 years of road grime from the engine compartment and repainting it. A good conversion is much more than just swapping the motor.

I'm installing a 400M and C-6 I pulled from my '77 Ranchero. I rebuilt that engine and trans four years ago and they have seen maybe 1,000 miles since then. I know the engine/trans and am satisfied with their condition. He didn't have the same confidence with his acquired engine/trans but was going ahead with the conversion anyway.

About costs. I'm doing this conversion on the cheap. Converting and balancing my 2-piece driveline was the most expensive component to date at $185 (I'm excluding a new front brake rotor and new bearings, seals, and slave cylinders for the rear brakes - cost me $303 yesterday at Napa. If the truck was already mine and brakes were good I wouldn't incur this cost). I had to buy new motor mounts from Auto Zone and used mount perches from a wrecking yard. I also needed to have the exhaust pipes modified to mate to my exhaust manifolds - another $90. I also needed to buy many small things that added to the cost. Luckily, I already had a 4-bbl intake and carb for the 400M. The 4-bbl carb came from an early 70s 460 and I only needed to rebuild it.

The truck cost me $1,300 and I've spent probably another $500 to do the conversion. Excluding the cost of the motor and trans, this is isn't going to break the bank. I've got about $1,200 invested in the motor and trans so if you add this to the cost of the conversion I'm approaching $1,700 to do it. It would have cost me a little less to install a rebuilt 390, but I already had the 400M so I'll be OK financially.

I'll have about $3,000 invested in this truck before I begin on the cosmetics (paint, carpet & upholstery) but the body is straight and rust free. I'll get decades of faithful service from my new truck so I can justify the cost and time.

Doing a conversion right is a real bitch and takes a lot of time. I love tinkering with these classic Fords so I don't mind the time. I'm fortunate in that I've been collecting classic Ford cars and parts since 1986 and have many parts laying around, a garage full of tools (including an engine hoist) and a large driveway to do my work. I also have several drivable vehicles so I can take this truck down for as long as needed to do the job right.

In 1992 when the trans in my ’81 F-100 went bad, I bought a 5-speed from a ’91 F-150 with a similar 300 CI six and thought it would just bolt right in. I was wrong. The trans was longer so I needed the shorter drive line from the newer truck. The shifter was in a different place so I needed to get the cover plate from the newer truck, and the frame cross member needed to be moved to accommodate the longer trans. My truck used mechanical clutch linkage and the newer truck used hydraulic. I had to remove the brake and clutch pedal assembly and have a clutch pedal rod and lever custom made by a machinist to convert my pedal’s linkage. What I thought would be a simple, one-weekend conversion turned into three weekends of hard work and countless hours of frustration and many phone calls and parts runs. This was just to convert to a newer transmission.

I couldn't imaging a kid doing a good conversion on his first attempt. He'd be better off getting a V-8 truck that wasn't running and then pull and rebuild the engine and tranny to gain the experience. My dad did this to me when I turned 16 back in 1972. He gave me a 1960 Caddy convertible (he paid $400 for it) that needed a lot of work. He helped me when I needed it but he also let me bust my knuckles just for the experience. It’s amazing how smart our dads can be from time to time.

Conversions can transform an OK vehicle to whatever you want it to be. They are rarely cheap or easy, but the joy of firing up your new baby for the first time and taking her around the block far outweighs the frustration and agony of the conversion, or at least it should or you are not doing it right.

A final note: many hot rodders put Chevy motors into their hot rod Fords from the 30s and 40s. Maybe I’ll put that 460 and C6 into the 55 Chevy that’s been sitting, unused, in my uncle’s driveway for the past two decades. That’ll really ****-off the Chevy crowd.

Bruce

 

I stand corrected!!!

In addition to being a Ford truck fan, I am also addicted to classic Mustangs. My second car was a ’68 GT Fastback with a 302, 4bbl, 4-speed and a traction lock rear end. I loved that car and wish I never sold it. Many 327 Camaros and a few 400 Firebirds wish I never owned it.

I responded to this thread because I own an ’81 F-100 with a 300 CI six as well as a ’68 Mustang GT/CS with 289 and I am converting a ’71 F-350 from a 390 to a 400M. I have some experience with both 6 bangers and V8s. I also have a ’68 GT-500 KR that I bought without an engine that I need to restore.

I just got my September copy of Mustang and Fords magazine. Beginning on page 27 is an article about a company called Clifford Performance from Corona CA, (909) 734-3310. They specialize in Ford in-line six cylinder engine performance.

I did not realize that the 200 and 250 CI small block and the 240 and 300 CI large block six cylinder engines have seven main bearings and, properly built, can withstand 7,000 RPM and make mountains of HP and stump pulling torque.

I encourage you to buy the magazine and read the article. Small block V8s beware of the well built sixes. A 302 cannot touch the torque of a 300 and, according to Clifford Performance, they can build you a 300 six that will make 600 HP at 7,000 RPM.

Evidently many of us have underrated the humble in-line sixes.

I can’t wait until my ’81 F100 is exempt from CA smog laws (in 2011).


Bruce

 

I am not trying to taunt you here, jowilker, it just upsets me when folks like you misinform and mistreat those who are trying to make good use of this forum. I just read one of your posts in another discussion where your reply to someone's question was, simply, "Ask a better question." What is that supposed to mean? Why can't you just be helpful? You must have some knowledge to offer.

Of course people don't put 6 bangers in to burn rubber. That's not what I said. This shows just how carefully you read my post!

BTW, I have never owned a Chevy of any kind, much less a Camaro. But who would care if I did? Are you saying Ford truck enthusiasts (like me) cannot have other interests as well?

 

>I am not trying to taunt you here, jowilker, it just upsets me when folks like you misinform and mistreat those who are trying to make good use of this forum.

Dan I am having trouble following your babble. I'm sorry that you feel mistreated. Please get in touch with yourself.

>I just read one of your posts in another discussion where your reply to someone's question was, simply, "Ask a better question." What is that supposed to mean?

You can't read plain english, He posted a statement, without a specific question. If you will go back you will see that he did indeed ask a better question. Sorry, it didn't go over HIS head.


>Why can't you just be helpful? You must have some knowledge to offer.

What would you like me to help you with?

>Of course people don't put 6 bangers in to burn rubber. That's not what I said. This shows just how carefully you read my post!

I went back and carefully reread your post three times "trying to make it burn rubber for cheap" Now Please tell me just what did you say here?

>BTW, I have never owned a Chevy of any kind, much less a Camaro. But who would care if I did? Are you saying Ford truck enthusiasts (like me) cannot have other interests as well?

Yup! When it comes to Chevys