My 302 is a turd, I am looking at a 351, main question, can I use the 302 ecu? I will stay with my e4od, just putting the 351 in.

 

To get the most from the 351 you need a ecu from a 351.

It will run like crap on the 302 ecu.

 

the part numbers are different, so if it ran, i imagine it'd run like siht

 

I'm gonna go out on a limb & say, with the same tranny, you'd be good ta go! The pinnout's are identical. Both Speed Density right?

I'd wait for a 3rd & 4th opinion.

 

yes speed density, when it comes to it I will try with the 302 ecu, if it doesnt work right I will find a 351 ecu. Hopefully I can find a whole donor truck with mass air. Being my wife drives the truck some times I am not going to do the manual swap but I will do the 351 swap. She tried to drive my 5spd ranger twice and failed, cant coordinate clutch\gas\shift in that order all at once.

 

Easier to teach em when their young. & of course after marriage,...........!!!

 

the 351 will be more of a turd than the 302...just be prepared for that...may make more HP but it has less torque...

the 351 cams are retarded 6 degrees and that makes it a real turd compared....

just fix the 302 or re-gear...its that simple...

the 302 and 351 ECM carry a different number because of the programming...other than that they are the exact same..

you WILL need the 351 injectors if you change and alter the timing for the 351...the 302 has a more aggresive timing curve than the 351...and the 351 I think has a fatter fuel curve...because of it being a turd....

honestly I;d stay with the 302 and do some add-ons...you'll be happier...


I'll bet if you freshened it up it would run a ton better...

 

I would guess that it would run lean because of the extra displacement. If you switch to MAF you'll need the computer anyways.

 

Ok thanks, I was going to change the cam, I know a good 351 cam would wake the engine up but if the 302 is a tad better, I will look into a cam change and find a mass air truck. I just need a little more power from the truck. I know non efi 351 would kick the 302 to the curb, and a 460 is not an option in this truck due to the pollution ***** here in Jersey, and I have 8 more years to register it as historic, they actually "open the hood" to make sure everything is in its place, if it werent for that a carbed 429 would be under the hood. I can at least make it pass emissions.

 

cam is fine....just make sure its a roller...those rate a tad faster than flat tappet...

then wake it up with headers and 2.25 duals...that will help alot..

cam swap is alot more expensive at the cost of tearing it down to do it and the gain is negligible....without proper ECM tuning...

what gears and tires?

even the carbed 351s in the late 70s and 83s are turds....I know..been there done that...done many 351 swaps from 302s...the 351s were wimpy compared if a better high performance cam isnt used...the 351 cams were ALL retarded even the early ones after 72...its ground into all the factory cams...you have to get a aftermarket cam to get away from it....