Hey guys. Im new to this site, but I have lots of questions so you'll probably be getting to know me. I recently purchased a 77 F-150, stepside short bed, with a 300 inline-6, 4x4. The truck is in fair shape and the engine is in excellent shape. However, I bought this truck with the intentions of lifting it, putting some rather large tires under it, probably a set of 38's or bigger, and then utlimately hitting the mud with it. My first question is regarding the engine. The I6 is obviously one of the better engines ever built, but lacks the HP I'm going to be needing. What engine would you guys recommend for this swap given what I want to do with this truck? I have been thinking about the 460, but Im afraid of what other modifications this large engine will make necessary. Such as the front end. Will the stock front end hold up to this beast? I know that the tranny will need to be changed, as will the rear-end. Also, will this engine mount easily or require substantial modifications to the engine compartment? Also, what do you recommend on finding an affordable replacement engine. Paying $2500 for a rebuilt 460 is not in my budget. Thanks and I appreaciate the advice.

 

Welcome to the forum.
The 460 will make plenty of power, the front end and rear end will hold up and since you will be lifting it, you will have stronger front springs to hold the extra weight. The bellhousing bolt patterns are different as are the frame mounts for the engine.
For good power with less weight and expense, I would recommend a 351W. They are easy to come by and have the same bellhousing bolt pattern as your 300. 302 mounts and such will work too. May mid 80's trucks had 351HO's in them so you can get all of the front accessory drive stuff off of one of those if not the whole engine.

 

Thanks for the info. I started looking today for a 351W and had limited success. I managed to find two. Both of which are at salvage yards. One is $550 and the other $350, both of course require an exchange with my I-6 300 for that price. Do you think these sound like fair prices? The one that is $350 is actually a 351 mod. in a 79 bronco and the other one is I think he said is in a mercury and is a 351W ($550).

 

Were these in cars are Vans ?

IMO, The Van 351W engine is the way to go as they come with a rear sump pan,

 

The 351W is in a car. I believe he said a mercury, but I couldn't understand him very well. The 351 mod. is in a 79 bronco. The 351 mod. won't match up to my bell housing will it?

 

The 351M shares the 400/429/460 B/H bolt pattern

 

If the 300 is in excellent condition as you say why not stick with it? These engines are not high reving, but can be absolute torque monsters which is what you would need with the 38s. For more info on these engines check the inline 6 threads on this site.

 

Yes the 300 is in excellent shape. No leaks and cranks up first hit everytime. It does have plenty of power for a 6, but not the kind of power I want. What I have planned for this truck is a 6 1/2" suspension lift, 3" body lift and 38" tires or maybe even larger, perhaps as big as 44's. So I don't want to be limited to what I can do with this truck on down the road because it doesn't have the power. I do want to hang on to the 6 for other projects. It's a great engine.

 

What kind of power are you looking for? There are many 300s that are putting out some big numbers for any engine, not just a 6 cyl., check out col. flashman's build and you'll see what I mean. As I stated, the 300 is an excellent torque engine at low rpm which is what you would need to get those big tires moving. With the setup you are describing I take it you are going for off-road performance rather than speed. The 300 is ideal for this as it delivers it's power down low where as a v8 needs to be revved. It also has a stronger bottom end with seven main bearings for six cylinders verses five mains for 8 cylinders. I'm not trying to say you shouldn't do the swap, it's your truck after all, but don't write the 300 off as a low power engine

 

Plaincowboy - been there / done that. I took the 6 banger out of my effie and built a rip-snortin / ashphalt churning downright SCARY 460+ monster (back when gas was $1.30 a gallon when it was "high"....). If I'd had ANY idea it was getting to what it is today, I would have rebuilt the 6 banger and that little - bitty 1 barrel carb!! Sure... Harrison (the truck) is a BLAST to drive...... once every 2-3 weeks (when I can afford it). I would not put a 460 in it unless you own a gas station....

Meet Harrison.... http://us.mistynewbeak.biz/html/harrison.html

 

The 300 is one of the engines of choice for the rock crawler clubs around here.

"300 and T-18 are bullet proof " some of the members claim.

Some of those rock climbing trucks are ludicrously lifted.


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Each engine has its place. The 300 is great for low end torque, (Why the rock crawlers like it), and it does better in mud in my opinion, cause you can control the amount of power at the wheels better, (lower RPMs), and it's less likely to spin the tires causing you to get stuck. IMO.

If you want the truck for racing, or spinning tires and slinging mud all over the place. the 300 isn't good for that. I'd say the 351 mentioned earlier would be a good engine for that.

Heck, I had a 1972 F-250 390-V8-4Barrel, that would get stuck all the time. Slightest touch of the pedal and the tires would spin off, if you were on any other surface than pavement. Rough road, empty bed, low speed, steep hill, gravel road, high gas pedal, bouncing driver, equals chirp, chirp, chirp, chirp, stuck.


Just my two cents.

 

Alright, I think you guys might have sold me to keep the straight 6. Im going to look into it a little further and see what I can do to beef it up. So if you have any suggestions on where to start, then throw'em at me. Keep in mind the engine is in excellent shape, but it's still almost 30 years old. And I don't have any type of history, other than it's the original motor.

Oh and to answer the one poster's question. The money for gas isn't a concern. This truck is going to be strictly an off-road play toy; mud & moutains.

 

Here is a thread in the off road forum on 300 I6, that's worth a look at.

https://www.ford-trucks.com/forums/s...d.php?t=468028

 

Thanks bro.

I've been looking around at other posts and what others have done to their I6's to get the most out of them and it's really starting to sound a little on the expensive side...lol.