Motor swap, compatability issues?

Reply Subscribe

Thread Tools

Search this Thread

Mar 22, 2010 | 12:54 AM

Snickashio

Thread Starter

New User

Joined: Mar 2010

Posts: 4

Likes: 0

Motor swap, compatability issues?

I've got a 1996 F-150 with the 4.9. I have a 1994 F-150 with the 302, and I'd like to swap the 300 out for the V8. I've heard i'll need the motor mounts, wiring harness, computer, and radiator from the donor truck. However, I've been told that there may be some compatability issues as my 96 is OBDII and the 94 is OBDI. Also, if the donor is an automatic and my truck is a standard, I've heard I'll need a computer for a 302 that had a 5 speed as the computers differ from being auto/standard. The big question is, can I do this fairly easily given the fact that I have the whole donor truck and everything I SHOULD need along with it?

Mar 22, 2010 | 09:42 AM

Conanski

FTE Legend

Joined: Jun 2006

Posts: 31,930

Likes: 1,499

From: Ottawa, Ontario

This is gong to be a difficult swap, the big problem is the engine wiring harnesses are not stand-alone they are integrated with the chassis wiring so they won't simply unplug. It's further complicated by the fact one of the trucks is OBD-2 which has a lot more wires. Even if you had a '96 302 truck to use a donor there would still be some wire splicing to do and that's besides all the other hard parts that need to be changed when going from the inline to a V8.

Mar 22, 2010 | 07:32 PM

Snickashio

Thread Starter

New User

Joined: Mar 2010

Posts: 4

Likes: 0

The only concern I've got is, How much wire splicing is gonna need to be done? So much that it makes this whole swap not worthwhile?

Mar 22, 2010 | 09:55 PM

Conanski

FTE Legend

Joined: Jun 2006

Posts: 31,930

Likes: 1,499

From: Ottawa, Ontario

If I were doing it I'd take the approach of maintaining the OBD-2 system and simply adding the wires needed to run a V8 instead of an 6-cylinder.. which includes but may not be limited to a few for the extra two injectors.. you'll have to compare wiring diagrams to know for sure. Then you'll only have to find an OBD-2 5.0 computer to plug in and a crank sensor and balancer for the '94 motor and you'll have a functional vehicle. What that means of course is the only thing you'll be salvaging from the '94 is the engine.. so you'll have to decide if that makes it a deal breaker or not.

Mar 23, 2010 | 12:15 AM

Snickashio

Thread Starter

New User

Joined: Mar 2010

Posts: 4

Likes: 0

That makes much more sense to me now, but If i wasn't concerned with keeping the OBD2 then do I have any other options? The truck will not be a daily driver, She'll only be coming out every so often. I can live with trouble codes and check engine lights. I'm just worried about functionality. It seems like alot of wiring trouble to keep the OBD2. That and I've got a mint `94 302 w/ only 70,000 miles, so gettting a OBD2 302 could be the deal breaker. any suggestions? or should I just buy a whole outfit w/ the V8 and swap the lift/body over?

Mar 23, 2010 | 12:39 AM

Snickashio

Thread Starter

New User

Joined: Mar 2010

Posts: 4

Likes: 0

I appreciate the input, it's helped a bunch so far. When you say "simply" running the extra wires to run the V8, how simple are we talking? If I could get by doing that then it make it a heck of alot easier than worrying about the other harness from the '94 etc. It would probably be just as cheap and easier to find an OBD2 302 computer and run the wires as needed, rather then screw around with the older OBD1 donor. Any more input/suggestions are appreciated. Thanks!

Mar 23, 2010 | 09:59 AM

Conanski

FTE Legend

Joined: Jun 2006

Posts: 31,930

Likes: 1,499

From: Ottawa, Ontario

Yeah like I was saying, swaping the '94 harness into the '96 is a massive undertaking since the engine and chassis wiring is all interconnected on both vehicles and they are not at all the same. Color codes and likely different and there is a lot more stuff on the '96.. 104 pins at the OBD-2 computer versus only 60 on the OBD-1 system.

What is it about your '96 that you don't like and why are you even considering a 5.0 truck? That is a step backwords from the 300I6 in some respects.