I have a friend with a 1990 F250 4X4 with a 302 5 speed. He is not at all happy with the performance he is getting from the pickup. He was thinking of going with 351 but would like to know what it entails doing.

Any other idea for good performance enhancements?

Thanks,
Geoff C.
1993 F250 4X4 E4OD 460 big block!

 

All 302's are garbage unless they are new, that engine probably has 200,000 or more kilometers on it. Its too bad, that engine has probably lost most of its compression. A good rebuid would be the solution, also a rebuild of the bearings and u joints that would be robbing some power. I have seen many a 302 in my day and man the peices they can be... Id go with top end and rings, gaskets and push-rods, lifters and cam. All of which probably have wear and tear on em. Also check his Diff ratio. Anything 3.55 or higher is gargage (ie. 3.08, 3.27) anything that is made for highway fuel economy. If it is a 3.08:1 ratio try putting in a new set rated 3.73:1 or 4:10 this will give it that extra jam at the start, but for fuel economy would be garbage.

 

He will probably go with a new engine....it's a shame because he only has 90,000 original miles. Any ideas on what he is going to need to do a 302 to a 351 engine swap?

 

Probably nothing, The computer connections may be a little different. Check the injector size. Im guessing everything is the same. but ya never know with Ford. I dont know why youd go with a 351 unless it came from factory with it. 302 is not far off from the 351 at all. The 351 has a bit more pulling power but horsepower is only 5-10 more. For the gas your going to burn Id rather drop the clutch at 3000 rather than 2200 and stalling. I took a 302 F150 XL 4x4 for a spin yesterday, Not a bad truck at all. 12000 CDN thou. Thats 7500 for you folks in US. THats way to expensive for a '93 F-Series. 154000 KMs. All brakes, brake hoses and suspension components have been done. Still way to much... As for your 5.0 - 5.8 swap. I wouldnt bother. Just rebuild the 302 and put a larger cam in it so it can breath better. Rebuilding an engine isnt hard at all. Just grab a book and read along should be no problem if you got the tools. And dont be fool by the electronic wiring at stuff. what comes off goes on when you put it back together, just dont touch none of the sensors and use a little pick to pry the electical connector plugs there is a tab thats got to be bent back to get most of them off. SOme on both sides and some on one side... Good luck bud

 

For the easiest swap, he'll need the complete engine wiring harness, engine compartment harness, computer, Y-pipe, & all accessories & brackets. There will still probably be a few cab wiring mods, but not enough to justify swapping THAT harness. I have a '96 MAF 5.8L but you should tell him to look locally first. I've done a similar swap to mine and a friend's, so I'm fairly familiar with the procedure.

Tell him to start by diagnosing his current engine. It may just need a couple of tune-up parts.
Pulling codes
Reading a vacuum gauge