I have a donor truck that has a 351w in it and its a 1990. My current truck is a 97 F250HD and has a 351w in it and runs smooth but rich. I would like to pull the 351 out of the donor truck and rebuild it as a spring project. Question is other than the difference in cams, what other differences are there? Both are OBD1. If I was to pull it and rebuild I would want to give it more power what could I do to the donor 351 to get more power?

 

I would try and fix the rich issue first. Once that is done, I would pull both engine, swap the 90' long block in temporarily and build the 97' block. But first figure out the running rich. Chances are if you don't it will be there with the new engine.

 

The only other difference besides the cam is with the distributor, the '97 has a steel roller cam so the distributor has a steel drive gear, and the TFI module is on the fender in '97 vs on the distributor in '90 so the PIP module and wiring is different. You can modify either distributor to work with the other motor by simply changing the drive gear. The cam to use in the '90 is the Crane 444232, that will give that motor a little more cam than the '97. The Thermactor(air injection) systems are also gonna be different on these trucks but functionally they are the same so you could use either one or eliminate the whole mess altogether if the stock cats are no longer present.

 

I live in Northern VA so the cats have to stay. To throw another issue is that the donor has a ZF5 and my truck has the E4OD.

 

That has no impact on this swap.

 

Find a set of GT40 or GT40P heads off of Explorer/Mountaineer engines, like 96-01, take em to a machine shop to get the head bolt holes drilled to 1/2 inch (302 bolts are smaller than 351), put a set of 1.7 roller rockers on with your stock cam, and be done with it. This is all speed density friendly, but IIRC the 97 SHOULD be mass airflow.

 

And if you do end up rebuilding one of the engines, opt for a little bit higher compression. Nothing outrageous, but a nice little bump in compression will give a good bump in power along with the other mods I stated

 

Thank you for the insight I'm going to start pricing out potential options to see how much I need to put away. Once I make my mind up I'm sure I'll be seeking some more advice. The seat swap from bench to bucket worked just like you and I discussed Evan thanks again for the help on that!

 

Glad that worked out for you.

 

It's actually far more likely the '97 is OBD1 SD, Ford held over the OBS HD truck in '97 so most HD trucks(anything bigger than an F150) did not get the OBD2 system until the all new SuperDuty truck was introduced in 1998. Exceptions were the Cali spec trucks that were OBD1 sequential mass air starting as early as 1994.

 

My truck is 100% still OBD1. Didn't the Lightnings have G40 heads? I remember someone posting something about that.

 

Yes the Lightning 5.8 had GT40 heads and the uber desirable tubular GT40 intake.. but they're a rare find in the junkyard or even on ebay these days.

 

Oh wow, I had no clue. Thanks for the good info

 

cam. that's only difference.. 97 has a roller cam 90 does not.
you can retrofit a roller setup into the 90 block though