New to the forum but I have done some research on here which led me to swapping out my 5.2 to a 5.9. The swap is done and the truck will start and run. Problems are that it runs hot. I left the wiring harness from the 318 and that caused me to have to use the 318 fuel injectors and I also have the 318 computer which I will be swapping soon. For some reason the timing is way out, It could be as much as 45 degrees advanced with the distributor set to the center. I put a cam that increased lift to .480 from .410 i believe is stock and also have headers. Is this too radical of a change for the stock PCM?

 

I would change the PCM, ASAP! If you have your 318 PCM running a 360, THATS a radical change for your stock 360 PCM. Get a new one thats flashed for a 360 because the way you're running it now, you're not getting 100% performance out of that 5.9 dude!

 

simply put, yes going from a stock 5.2 to a 5.9 is a HUGE change, but going to a 5.9 w/ that kind of work done, you should probably get a proper tune for the PCM

 

My '99 originally came with a 318, and still has the stock 318 PCM with the 360. Though, I have it tuned with a Superchips 3815, and I'm running a stock cam. Never had any issues.

Runs fine on the stock tune, too, but I like the Superchips.

I thought about installing a bigger cam when I did mine, but I wanted to avoid any problems and make sure it runs perfect before upgrading stock parts.