Okay so I recently bought a truck that my dad actually ordered new in 1994. 4x4 f150 XLT with the 351w and e40d trans. The old motor in it has seen some hard miles since he sold it and I want to rebuild or replace it. What I want to know is what horsepower mods can I do for 3-5k? I will be using it for towing my sxs on an aluminum trailer(total weight ~3k) and cruising my farm. I don’t really care about fuel economy and I don’t have to pass inspection here in good ole South Carolina. How much HP and torque could I get with a 3-5k budget?

 

300 hp is a threshold for the stock injectors. Above that and you need bigger injectors with proper tuning. Bang for buck is a set of GT40 heads, long tube headers (into a Y pipe and single 3" outlet, high flow catalyst, then your muffler of choice), 1.7 ratio roller rockers with factory roller camshaft. A hybrid 5.0 L truck upper and heavily port matched 5.8L lower seems to be an improvement but keep it within the realm of stock injectors. If the bottom end of the engine is healthy then the above is under budget. If the bottom end needs a full rebuild with machine work, you'll end up right in the middle (roughly speaking, unless you find screaming deals, or prices are higher than I realize).

If the bottom end is in need of a rebuild, and you're willing to drop some money on an aftermarket computer (like Stinger Performance's PimpxShift) you could go stroker motor with better heads and bigger cam. I think it would be pretty easy to blow the budget going this route but you could end up with a real fire breather. I know much less on this course of action so I hesitate to offer any advice of substance.

An alternative is look into crate engines. I know even less about that option than strokers.

You may also want to consider a 460 swap. Though you'd need a BBF trans to go with it (your current small block bell housing E4OD won't fit the big block).

 

First off, do compression test, that will tell you the basic condition of the motor.

The cheapest/easiest/quickest to the most expensive/hardest/longest:
headers, intake, cam, heads
- headers, shorts bolt on, long tubes will need custom exhaust.
- not much options for stock replacement intake, Edelbrock 8331
- many options for cam, recommended to get new lifters and valve springs
- aluminum would be better, port your E7s yourself

Start pricing stuff out, should be easy to fit in your budget, unless your short block needs replacing.

 

I actually have a 408 stroker motor that was built about 8 years ago and has never been taken out of the plastic. Just didn’t think of putting it in the truck because I didn’t know how hard the efi stuff would be bc I know the stock stuff definitely wouldn’t work, and I’d like to still be able to take it to the beach if I wanted and I didn’t think a stroker motor would be good on long drives.

 

It probably won’t work with the stock EFI system but that depends on the specs of the camshaft and other parts used in the build. Assuming that is a Speed Density system you can only change things so much before the computer cannot compensate. Mass air is a little more flexible but it also has its limits. What difference does increasing the stroke have to do with how many miles you can drive in one direction?

 

I know it isn’t one of the maf systems so I’m assuming it’s speed density. And I don’t guess it does, I was more saying I didn’t know if a 408 could be a streetable motor. It was built to go in a drag car so I wasn’t sure what all I would have to swap in order to make it reliable.

 

also I was under the impression that towing with a stroker motor wasn’t a very good idea

 

Strokers tend to build more torque than the engine they're based off of. So they're far more suitable for towing. Unless this thing is built to be a 12:1 compression race motor, and is something more realistic like 10:1, and doesn't have a cam that builds everything at the top end, it's going to be fine.

If it were me, I'd take the money you're considering putting into a new motor, get a junkyard intake setup off an EFI 5.8, and then buy the PimpX with trans controller, and put it together.