I have never rebuilt mpi/computer run engines. I need to know if you can change the internals of a 5.9 Magnum without it affecting the pcm.

 

just reset it by disconnecting the battery for 10 minutes when complete...while its disconnected turn the headlight switch on for 10 seconds....this will reset the pcm, and relearn the new componants

 

then PM hemifever for a custom SCT tune. 375 for the tuner with the canned, stock and custom tune.

Can't beat it.

 

i'm not sure what the question is, but if you bore it significantly, or stroke it, or put in a big cam or something, you'll need to retune the pcm to get the extra power out of it, possibly even to make it run.

if you replace stock parts with stock parts, there's no change needed.

 

I just want to raise the compression and put slightly bigger valves in. I don't want to bore the cylinder. I'll also put a slightly bigger lift cam in.

 

not sure with valves...direct replacements is what i was referring to.

 

How much do you know about building motors? I ask because boring isn't really an optional step if the motor needs it.

The motor will probably run with a factory computer but you will need a performance tune to get it running the best and to get the most power. With a 1997 you are limited to what you can do tuner wise. I have heard that SCT tuners don't work. You may have to get a B+G flash.

 

the cylinders don't need boring, just a little honing. they are in good shape. ive rebuilt several engines, just not any controlled by a dang computer. I'm a pre- '73 muscle car guy.