Ok, so here's situation. I bought an 87 f150 it has a 4.9 and a granny 4 spd. Its a good truck but needs more power, and it just so happens that a very special 1991 f150 with a 351 Windsor with an a4od came up for sale.... but this isn't any truck its the truck I bought when I was 16 years old, so it has some sentimental value to it, not to mention it had good power and a sound that'll give any man a full blown hard on. But enough of the past, I need to know exactly what I need to do the swap, I've read every swap story on the site but none with my exact situation. I know the motor mounts need changed along with the computer and probably the wiring harness, and I'll need a new flywheel. Is that everything? Will the fuel delivery system on the 87 work for the 351? Are there any major issues with the swap concerning the difference in years?

 

Since your truck is an '87, your old six is carburated. The '91 351 is fuel injected. So your choices are going to be...the easy way, find a carbed 351; and a flywheel if you plan to use your 4 speed. Or the complicated way; use the EFI 351, and you'll need to get the engine bay harness, ECM, as well as the underdash harness, possibly the dash and instrument cluster for the EFI/engine warning light. You'll also need to get the high pressure fuel lines, the in tank fuel pump or pumps if you have the dual fuel tanks. Personally, I'd go for the carbed set up...

I'm doing a similar swap, except my truck is a '94 with an EFI 300 I6 with a 5 speed and I am swapping the six for a '95 351. I bought the 351 complete which means that it still had the alternator, ac compressor, air pump, and cooling fan still attached. The guy also threw in the engine bay harness, the engine perches, the Y pipe, airbox and rubber air ducts, radiator, and fan shroud. I did buy 28oz flywheel and clutch kit, an ECM for the 351/5 speed combo, to replace my current ECM for the 300/ 5 speed. Since I'm doing the swap outdoors, the rainy weather has slowed my progress somewhat. The other stumbling block was when I found out that my radiator core support was rotted out where it mounts to the frame. Removing the core support has given me an unexpected benefit by giving me a more direct pathway for removing the old six and 5 speed gearbox together.....