A friend of mine has asked me to research for him on building his engine. He is getting ready to rebuild it and wants a little more juice that will be reliable and last a long time. He currently has a 89 F250 with a 351W. He'd like about 300-350 hp out of it. My initial thoughts for him would be with the full rebuild, to put in a larger cam, port the heads, get larger injectors & throttle body, better intake, headers with a good exhaust system, upgrade the ignition. I thought that should get him close to where he wants to be, but I'm not sure what computer modifications would need to be done though. Please advise as to what all would need to be done with the computer to compensate for the modifications. Also, do you think I can get him where he wants to be with the modifications mentioned? Any suggestions are welcome.

 

He would need high flow injectors and possibly a more powerful fuel pump. Other than that i think the computer would automaticaly compensate for the better airflow through the engine and automatically increase fuel flow. I know someone who did basically the same thing with his Camaro and had no computer troubles.

-Jon

 

he doesn't change the engine displacement, I second what Ford4ever says. The computer is designed for the 351 cubic inches, no matter the hp. You only need to get higher psi injectors and a new fuel pump. Besides, if it is an 89, it sounds like it could use 'em anyways He shouldn't have too much trouble getting it in that area, as I know someone who took a 351 from junkyard condition and brought it to a very respectable 332 hp. One in better condition should have no problem.

-Flea

 

HI!... Well I took a junkyard 351-W and got it ti 532H.P and another to 875H.P. Now I'm working on a 351-W = 427 stroker that is going to make 725H.P naturally asperated and then going with at least a 250 BIG SHOT NOS kit. That will make it at about 975H.P. I'm also working on a 5.4 crate engine that will be worth about 750H.P with a MAGNACHARGER at 10 PSI and a 250 BIG SHOT. Well, I guess that's why they call me the "H.P FREAK" lol!

 

Thanks for the info guys. Bigger injectors were on the plate, but I wasn't sure on the fueld pumps. That will be a pain because I believe he has two in-tank pumps for the dual tanks. I'm sure he'll probably bore the motor .030 as it has 117,000 miles on it now with the rebuild. Will that cause the computer to goof up or would modifications only be needed if he drastically changed the displacement by stroking it.

Flea - I think 332 would be a good number for him. I don't suppose you could get specs on what was done to your friends 351 could you?

I've seen several buildups that would easily get him where he wants to be, but they are all for carbed motors. I've also never built up a fuel injected motor more than the basic headwork/exhaust/etc, so that's why I'm aprehensive with all the computer & ignition stuff.

 

im looking to do something similar with my engine, except i have a 302. right now, im really considering the edelbrock power package, which includes aluminum heads, bigger TB, aluminum intake and i dont really remember what else. you should look into it, they have the packages for 302's and 351's. also, if hes gonna change the cam, i believe that hes gonna need to convert to a mass air system (if his truck has speed density). the guys at summit should be able to tell u for sure, shoot them an email and ask them. good luck with the engine!

 

primetime... I don't know some of the exact specs (i.e. timing, compression, bore and stroke, etc.), but I do know that he went with some gibson headers, Holley intake manifold, I think 30# fuel injectiors, dual 62mm throttle body from a 460 (don't ask me how it fit), forged pistons (have to ask about brand), crane street cam and some other things... I'll try and get the particulars from him if I can.

-flea