4.3L V6 to 4.8L V8 conversion 2000 Silverado

[sc_customs]

I need help!!! I've recently took on the task of converting my 1999 Chevrolet Silverado 4.3L V6 to the 4.8L V8. The motor is out of a 2000 Silverado. I finally got it in after having to get new fuel lines, mounts, and an assortment of other things that didn't covert from the V6. I am extremely close to finishing this project. There is just one small problem. When I turn the key, nothing happens. When the key is in the run position I get all my gauges, except oil pressure. I would just assume since the motor has yet to be started there won't be any indication of oil pressure. I have tried everything in my knowledge and to no avail. Like I said, I need help! Anyone have any ideas???

[frankendart]

Did you remember the basics?
Like hooking up the starter? If it's an auto trans, check the Neutral Safety switch. Is it in park? If a manual trans, are you depressing the clutch? Is the entire starter circuit hook up? Does it have a LOW OIL PRESSURE SHUT OFF that needs to be reset?

I know there's are stupid questions, but most of the time it's the most simple things that screw up an otherwise great project.

[sc_customs]

Turned out to be a bad ECM aka PCM. Thanks for the suggestions though!

[liftedsilverado]

I know this thread is really old, but how hard was the conversion?

[sc_customs]

Originally Posted by liftedsilverado

I know this thread is really old, but how hard was the conversion?

Hard. V6 to V8, while worth it, has been the hardest conversion I've done.

[TonynWV]

I have been considering this myself as Chevy has chose to turn their backs on the manual tranny drivers. I thought maybe since I had to go that far though of just using a 5.3 but then Id not be able to find a manual tranny computer for a 5.3. Is there any hidden pitfalls? Just a lot of wiring? Be nice to find a shop that done this stuff...lol.