3.4 dohc to 3.1 ohc
 

Am I able to put a 3.4(z34) motor from a 95 monte into a 96 monte with a 3.1(LS) motor? Are the wiring harnesses interchangeable?

RE: 3.4 dohc to 3.1 ohc
 

Get a 96 3.4L, along with its engine wiring harness, and it will be a direct drop in. You must keep the 96+ obd2 to keep emission compliant, and besides the 95 engines probably have electrical system differences because they're not obd2.

Any particular reason to want to swap to a 3.4 dohc though? They're more expensive/harder to work on, and honestly have less aftermarket than the 3100 or 3800.

RE: 3.4 dohc to 3.1 ohc
 

my buddy needs an engine for his 96 whose 3.1 crapped out on him, and my 95 with a 3.4 crapped out on me altogether. the engine is damn near the only salvageable thing in my 95. So are you saying i can use a wiring harness from a 96 with a 3.4 to put my 95 3.1 in the 96 vehicle?

RE: 3.4 dohc to 3.1 ohc
 

Thats tough- I doubt it. I'm definitely no 3.4 dohc expert, but most engines that spanned the gap from obd "1.5" to obd 2 (ie 95 to 96+) had changes to various engine sensors and such.

I thought you just wanted to put a 3.4 in, which is why I was suggesting getting one from a 96 or 97 Z along with the wiring harness- as that would be plug and play.

I guess it would probably work in reverse too- if you used your trans, your wiring, your engine/pcm- as long as he doesn't have to pass emission testing. But what you'd need to look into is the difference from 95 to 96+ as far as that body connector goes- where the engine harness plugs into the rest of the car at the firewall. I'd bet the obd plug wiring is different, but there may be other differences to address as well-possibly even with other systems.

RE: 3.4 dohc to 3.1 ohc
 

I'm just going to end up selling him the whole car so he can fix it up an sell it. I'm too lazy to do it myself. It needs an entire new front clip, cv axle, and either A-arm or ball joint. It's lookin pretty sad right now. But either way, I still appreciate the help, effort, and time you took to try helping me out.