Hey guys I'm looking to see if I can make a 351w out of a 85 f-150 work in my 96 302 f-150. Its out of an old truck we have sitting around and it isnt seized so. How could I swap this and retain the efi? I want the efi because of it general benifits. Is it possibe I could use the top end from the 302 or would that destroy the power? I want to build the 351 up a bit as well. I was thinking a 393? Is it even going to be worth swapping this or should I just mod the 302? I'd like an engine that I don't have to rev to 3500 rpm to get going faster than a minivan. Am I correct in thinking that a 351 will make a lot more torque and get the truck moving better? I'd like to keep the gas mileage on the highway reasonable and I am assuming I might gain some in town? Any info on how this might be done would be appreciated.

 

Yes you can do this, I did almost exactly the same thing with my '90.

You need find a complete 5.8 EFI intake, a late model 5.8 distributor and the '96 only 5.8 crank balancer, EGR valve and DPFE tube.

No won't fit.. the 5.8 block is wider.

You will end up revving it more than that(because you can) but even a relatively stock 351 will stomp all over a 302, my truck was 3sec faster 0-60 with the 5.8 and walked up big hills on the highway without dropping out of OD or losing any speed.

My '90 was capable of close to 18mpg with the cruise set at 70mph but around town it got about 13mpg. That's just physics at work, the bigger the motor the more gas it burns in stop and go, if you want a hyper milage city vehicle buy a little 4cyl car.

 

I'm guessing I can buy the 96 only stuff new as I think I might have a hard time finding it. Would I also need a 351 computer or will the 302 computer run it? Does it bolt right up to the transmission (Code U) or do I need a different flex plate?

That mpg is around what I get now and I would be plenty happy with that. Is that with a relatively stock engine? Do you think it would decrease much with a 393 or mildly built 351? Ya I know I'll probably rev it just as high lol. Will it make more torque at a lower rpm to help it get moving?

 

Yes not common to find and expensive when it is.

The 5.8 will bolt right up but requires a different flexplate.. 28oz imbalance for an AOD/4R70w instead of 50oz for the 5.0. The existing computer will work for a mildly built 5.8, if you build a stroker with aftermarket heads you will need larger injectors, fuel pump, MAF meter, and a tuner to make it all cooperate.

Yes, cam, ported heads and full exhaust system on an otherwise stock motor.

A bigger motor will drink more fuel all else being the same, but a bigger motor can also pull taller gears or taller tires so you can gain back some of that with a modified drivetrain config. A 5.8 makes more torque at 2000rpm than the 5.0 makes anywhere, and a properly built 393 can make more torque than a stock 460.

 

The efi 351w distributors came with different gears, depending on whether the cam was flat tappet or roller. So if you use a 94+ distributor, youll need to change the gear, if you plan to use the 85 longblock as is.

My relatively stock roller efi speed density 351w, gets on average 18 mpg and thats rural/ city driving, as recorded at fillup. But my truck is reg cab, f150, 2wd, 3.55 gear ratio....with a 5 speed manual.

I tried a couple 302 trucks out but never cared for them.

 

How much power would the 302 computer be good for? I was hoping to get somewhere in the range of 300hp and 400fpt. Would this be possible with the 302 computer or would I need a 351 computer? How hard would it to get these power numbers out of the 351 at a low rpm? Can it be done with stock heads or maybe heads off of a mustang? Would it make it eaisier to get those numbers from a 393 or would it not be worth it without aftermarket heads? If building a 393 with get those numbers easier than I might be alright with going carbed so that I don't have to mess with tuning the computer. If I stayed carbed than I would need something to control the transmission correct? Hopefully I can get the motor pulled out later this week and I can see what kind of shape its in.

 

With tuning software, a stock computer is good for way more HP than you'll ever want or need. The problem, is whether or not your computer is supported by the software. There are stock computers out there that are heavily supported/used and would likely be a better choice than the one in your truck but that's all relative.

If you stay naturally aspirated, your gonna need aftermarket heads to get in the 300-400+ range or invest enough money in the stock heads, that you'll wish you went aftermarket. If you invest in mustang /explorer gt40/gt40p heads, once reworked, you'll still find yourself in the hole far enough, you'll wish you went aftermarket, as there will be way more potential.

If you choose to use a supercharger or turbo, even a stock longblock will make enough torque to put a smile on your face.

One thing you may be overlooking, is the stock fuel delivery, its limited and will need to be addressed, if you plan on making real power.