5.0 to 5.8 Swap
 

Okay here is the rundown of what I need to know. This isn't actually my truck, i'm just doing the work for him. He has a 1990 F250 with a 5.0 and a five speed transmission. What he wants to do is put a 351 in from a 90 Bronco that I have. My problem is this, the 351 uses a different firing order than that of the 5.0 he has because he has the non-H.0. motor.

What I want to know is can I just find another F truck with a 5.8 and just take the computer, or do I need to take the whole harness. And also does it have to be a manual transmission computer or does it really matter, im a Mustang guy myself and I know for my car I can use an automatic transmission computer with a 5 speed and it won't affect nothing. Any info will be usefull as I am reading up on everything I need to do this swap, thanks :)

It doesn't matter that the 2 motors have a different firing order, the injectors are batch fired with the SD system on these trucks and they are all wired the same way from the factory for both motors. You need a computer for a 5.8 with either a manual or non computer controlled auto(C6), most 5.8 trucks before about '92 used the C6 so it shouldn't be too hard to find.

Ok so any F truck with a 5.8 from 87 to 92 should have a computer I need? Just want to make sure so I don't have to make more than one trip to the yard

Any F series (or bronco) that does not have an E4OD or an AODE that is an SD batch system will work yes. These two transmissions are computer controlled and can create all sorts of havoc when the trans they are trying to control is not there

Ok and I have one more question. The 351 doesn't have the original exhaust manifolds, will the 5.0 ones work or will I have to find another pair of those also? Thanks

On the exhaust manifolds EGR might be a problem, 5.0 connects to intake I believe and 5.8 connects to front end of right exhaust manifold.

yes Wag53 is right, the 5.8 EGR valve connects to the front of the passenger side exhaust manifold. Also, hopefully you're planning to do something with the exhaust because I also believe that the outputs are at different angles between the 5.0 and 5.8 manis

If you use the 5.0 manifolds they will bolt up to the 5.0 Y-pipe after you widen it. It's also pretty easy to drill and tap a hole for the EGR tube, you'll just have to create a fitting for it..

Alright thanks a lot guys, Ill let you know if I have any more questions :)

Ok im having a hell of a time finding a 5.8 computer now.. I was thinking though, if firing order don't matter, then what is the difference between a 5.0 computer and a 5.8? The only difference between the two engines is its a little wider and taller, all the electronics are the same.. :confused:

The fuel requirements are different due to the larger displacement, thus a different computer calibration.

I'm currently running a 5.8/E4OD computer on a 5.0/C4 in my 79 F-150. No check engine light and I like the way it runs better than my 5.0/AOD computer.

I've seen other guys here that have done the 5.0 to 5.8 swap and used the 5.0 computer with no trouble.

Ya but wouldn't the O2 sensors just set new fuel trim numbers anyway?

Sensors don't set anything, the computer does. The computer is programmed from the factory for the specific engine it will control, and there is a cartain amount of learning capability built in so a 5.0 computer will adapt a stock 5.8 fairly well given some time, but it may not run quite as well as the same motor with the matching computer.

Okay sweet deal, now I can finally start on this dumb swap haha