I've got a 89 F150 4x4 with a 4 inch lift and 33's. the rear axle is 3.55 ratio and the tranny a t 18. the 302 in it now is about shot. It runs about 3,000 rpms at 65mph. my question is can i swap a carberated 351 into and get enough power to keep from having to swap the axle ratio. with stock tires on it it runs about 3,000 at 60mph and i would hate to put 4.10 gears in it because it would run even higher rpm's. if i was to swap the efi 302 out for a 351 what all would be involved? would the tranny and motor mounts bolt up and what about the fuel pressure and computer. thanks

 

The 351W will bolt to your current trans. They use the same bell housing bolt patern. You will need to address the flywheel though. The 302 uses a 50 oz vise the 351W 28 oz. The swap is pretty much straight forward. You would have to think about a different distributor setup and possible radiator fan issues. ie... are you running an electric fan now? if so you maybe be able to get away with putting a themo switch on the 351W to turn on the fan. The 351W is a little more powerful. Your operating RPM's would be the same. You just wouldn't use as much gas as the 302. You might see a diffeance at the pump if you were to keep track of the milage and compare at the end of a year. But since you are going to a carb'd motor the milage sort of goes out the window. You might at best get around 13 miles to the gallon if you are lucky. The motor mounts will also bolt up. The biggest differance between the blocks is the deck height and width of the intake manifold. As far as the fuel pump goes you can run a adjustable fuel regulator and a block off plate on the timing cover for the mech fuel pump pad. You may also need to upgrade the exhaust depending on what size pipes you are running now. If you have 2 1/4 pipes you are good to go. Anything smaller and you will end up ballooning your mufflers out. I found out the hard way. Hopefully this didn't confuse you too much.

 

Thanks, i get about 11.5mph now if i stay off of it. what does your truck get? Also what do it do about the ignition and all the computer sensor and the emissions?