This summer my sister bought a temporary F150 that she needed for a few months and was told it was a V6, she never looked under the hood until last night when she was putting it on craigslist and found out it's actually a 351 V8.


She got the truck for $600 so I have a possibility to get it for cheap and I was debating swapping it and the transmission into my 78. I don't know a whole lot about 351's other than somewhere around 96 or 97 they discontinued them when the modular engine was introduced and that the last 351 had low hp at around 210 but had around 320 pounds of torque.

I'm wondering what other peoples opinions on a swap like this are. I'm pretty sure the 460 in my truck now is somewhere around the same torque but has higher hp so the only advantage I can see in a swap like this would be fuel injection and a 4 speed OD transmission instead of the C6 in it now so the only real gains that I could guess now would be slightly better mileage but probably not by much.

The other thing about this would be if I end up not going with this in my truck, if I even buy the 351, is I would put it in my mustang which is a swap I was looking at last year. It should fit in the stang since the 95 Cobra R mustangs had a 351W in them and the frame is the same from 94-04, mines an 04. I'm not looking for a super high hp engine if I do the stang swap, mostly I'm looking for torque and if I want to up the hp I can always supercharge it eventually.

So what is everyones opinions on either idea? Right now I'm mostly leaning towards the mustang swap but since I will be tearing my truck apart this summer and starting to rebuild parts of it I might go that route as a resto-mod or something.

 

You will get MUCH better mileage out of the 351 and OD transmission, most likely in the neighborhood of 4-5 mpg. As far as the 460 and 351 being somewhat equal in power, that is not true. You will notice a large drop in power with this swap, especially once you have a load behind it.

 

Both are great swap opportunity's, and each in their own right could very well worth it.

If the truck is my DD or I would want to drive the truck more. This would be my first choice. Also it would be the easiest on the wallet because you'd have tons of room to play with. I would use Mega Squirt to power the 351 instead of trying to chop down the factory computer system.

A properly set up 460 without overdrive can get around 17 hwy, and probably less the 10 in the city. If your truck is stock it'll cost you around $1000 to get there, and that is if you can do the work yourself. Along with finding the deals.

Swapping the 351 in can get you a bit over 20 hwy or fairly close to it. Depending on if you choose mpg or setting it up to work as close as it can to a 460. With the swap cost of around $1500 not including the cost of the truck.

The above mpg figures your using electric fans, street tires, proper tune up, good exhaust with headers, and appropriate gears.

The car which I am no longer into personally will be quite fast with the extra torque, and need car specific parts to be hooked up. Parts which your 302 doesn't have because of the added deck height.

 

I was not expecting that it would get that much better mileage. The only reason I am more likely to go the route of putting it in the stang is because I will be using the truck as a part time DD/work and hauling truck and I need more power for what I will be pulling. The truck will end up with an electric fan though either way. I'm looking into the possibility of getting a new radiator from "Matsons Custom Radiator" in the summer since if I keep the 460 in it I plan on rebuilding it for more torque to try and get slightly better mileage out of it and still be able to handle loads so better cooling and an electric fan are definately something I'd like. Right now I'm getting about 10-12 on 91 octane with the truck.

I've only heard of Mega Squirt, it's a system you can hook up to customize your efi setting and everything but it becomes the replacement for the stock system right? The wiring in an efi engine to a truck that came carbed and still being able to use the gauges and everything that was stock with the truck is what I have been trying to figure out how to do.

My mustang has a 3.9 V6 in it not a 302 so it would be an adventure getting it into the car as well. What car specific parts are you talking about though? I was going to get some 95 Cobra motor mounts which should bolt directly up where the 04 mounts are. I'm sure there is other things to swap over as well but I'm not sure and haven't been able to check out an actual swap thread yet to see what things other people have ran into.

 

Sure it is a 351W? and not an M?

 

Can't say I've ever heard of a 460 getting that good of gas mileage. Consider that the EFI 351's only got 10/14 with the 4 speed auto.

One thing to note, the E4OD trans is quite beefy compared to the C6. IIRC, a E4OD will run into the firewall, so you'd have to cut that, plus fab a trans crossmember.


vs



Jameson

 

I think I remember reading that the 351m was done in 1983. If anyone knows the actual year let me know.

jgavac: What mileage are you talking about? The 10-12 I posted? That's what I've been getting with 91 octane and a few other people I know with them are getting close to it. The guy I bought the truck from tuned the carb great I guess, it's an edelbrock but I'm not sure which one.

I was hoping that the E4OD would have been small enough to fit without cutting. Wouldn't the 351 sit lower though than the 460 block does?

 

I was talking about the comment Ziegelsteinfaust made about the 17 mpg. If you're getting 10 out of a 460 with a C6, you're lucky. Mine only does about 5.

Yes the engine is smaller, but it doesn't sit lower in the engine compartment. If you compare engine towers from a 460 and a 351 side by side, the 351's are taller to account for the smaller block. They will sit at the same level.

In addition, the E4OD is longer, so you'll need to get a new driveshaft, and figure something for the shift linkage


Jameson

 

I don't know about the 351, but we had a shop truck, 93 if I remember right, regular cab, long box 4x4 with the 302 and it only got like 12mpg. It was terrible, and it seemed to run pretty good.

I always got about 9-10mpg with my 460s didn't seem to matter what you were doing either always right around 10.

 

That's how my old 87 was and that was an I6 but had a granny gear and I only got 11 at all times. I'm surprised yours only got 12, a friend of mine said he was getting 15 out of his I don't remember the year but I think it was early to mid 90's and he had a 302.

jgavac: Good to know about the height. I figured that I would need to change the driveshaft somehow. If I go this route I would have everything from the F150 so engine, transmission and drive shaft. If the driveshaft from the F150 doesn't work I'll just have the one from my truck shortened and I figured I would just fab up something for a shift linkage or see if I could get ahold of something that would work. That's another reason I was leaning more towards a swap with the stang because of all the extra fabrication and wiring I will have to do to fit it in the truck. The better mileage would be nice but it's a lot of work as well. What year is your 460? I'v always heard that the older ones from the 70's got better mileage than the FI ones from 80's


My sister is having the engine checked out tomorrow so I should know by the end of the week what I will be doing.

 

I have a '72 from a Lincoln in mine. Granted it's also mildly built, and most likely running rich. Even with the stock, smog choked '79 it had, still only got 6-7

If you want power, fuel economy, and don't mind fab, maybe look into a diesel conversion of some kind. I know a lot of people around here do Cummins swaps, and there's a guy who did a 7.3 IDI w/E4OD from a '89 into his 2wd '78 f250.


Jameson

 

Mega squirt is a do it yourself fuel injection computer. It is fairly easy to assemble, and it has self tuning software on the newest versions. I haven't played with myself as of yet, but my next engine swap will have it for fuel injection. I live in southern california so fuel injection doesn't do much for me besides a bit of drive ability.

The 3.9 swap to 351 is still fairly easy, but you'll need to gather more parts from the junkyard to make it work.

If you build the 460 for MPG is not really necessary, and all it really needs is bolt-ons unless its just due for one. The secret to mileage is getting the engine rpm as low as you can. Balanced with what you really intend to do with it. Also why do you run 91? Does your engine have the open chamber D2VE heads? If it does get a set of D3VE heads if you ever have valve or head gasket troubles.

My last truck I built was a 77 rcsb GMC C10. It had a 350 with a highly detailed build, comp 260 cam, full bolt-ons, and a pro built Q-jet. I ran 2.50 gears with 245/70/15's with moon caps, and I used a ac idle solenoid for cruise control. It would regularly get 20-21 mpg hwy with the solenoid set at 70. It was pretty doggy around town. Well down right doggy especially with anything in the bed, but when I added a 2200 rpm stall converter it pepped up quite a bit.

The big reason I got it that good was tuning. When the factory built things they net built them. So under pretty much any set of variances it would run fine. I only set my tuning up for one motor so I was able to fine tune it to it's real tolerances, where I live, how I drive, and a bit of season variances.

Its always in the details of how something is built. The factory builds things so they don't get them back with complaints. Also things like nvh, road noise, and engine noise can make big differences with buyers.

Also lets just get down to cost. How much extra is the average buyer willing to pay for a "perfect" vehicle. When I finely tuned my truck it would last 2-3 weeks, and then I would have to reset it again. Not a big deal, but it would take about 30 minutes. Otherwise it would trickle back down to where a stock motor would get with my bolt-ons.

If you take the stock 351, and detail it as much as I did. Especially with the OD you'd be where I was with broader performance. Set your rear gears so at 70 your turning 2000 rpm, and bolt-ons. You'd be in the money as far as trucks go.

If I had money I wonder what a new 3.7 with a 6 speed could do in a lighter chassis.