I used to play around with the old 2.8's. I even made my 82 camaro V6 into a HO 2.8 by pulling a cam from one of those X11 Citation. Course that was before all the better 3.1 parts came out.

I was talking about the bottom ends not staying together. I was a GM tech 84-90. Of all the major engine repairs one of the most common was the 2.8 and 3.1 cranks and rods. Most of the times it was the stick shifts. Basicly you could destroy the motor in a single night. The older style control moduals would start to retard the time about 6K. The motors would not do much more then 6200 RPMs with any type of load. That was enough to strech the rods out. First you get the drop in oil pressure then the knock in the motor and next the spun bearing. We had one kid that was on his third crank kit. Sevice manager told his dad the next time it will not be covered. Under warranty we put in complete crank kits. I alway thought it was the rods mostly cause we would find them in various stages of streaching in the same engine. I got a few in at the knocking stag out of warranty and we where able to resize the rod and save the owner a few bucks.

Nomally i would say get the rods "peened" but since cracking was not an issue on any of the pre-spun bearing it seems pointless. You want to make sure you get a real good set of rod bolt. You did say you spun the bearing so you will be replacing/regrinding the crank and the rods? Maybe there is an upgrade out there?

 

What year and model 3x00s heads and intake do you look for to swap into a camaro? Will there be clearence issues with the distributor and intake? sorry for the hijack.

 

found some disappointing info tonight, i can't use the 3500 heads on my 3.1. so i'm gonna have to upgrade to a 3.4 block (if i want to use 3500 heads), or find better flowing heads that will fit the 3.1

 

cant you port the stock heads? or wont that be enough

 

porting the stock heads is only good for about 10hp. you can get more, but it's going to require a whole heck of a lot of porting.

 

im not sure what gains you get from porting stock heads, but you can only port them so much, which is why a lot of people get aftermarket heads that are already larger,and have more material to port them more,if you choose so

 

Make sure you get the factory roller rockers that go with those heads. The rockers are keyed into the pedestals and bolted down tight and are not adjustable, that is one reason for getting the proper length push rods. You will need to use 3.4 cam as the 3500 uses a roller cam, but the 3.4 oiling system does not work with roller lifters.

 

the heads i'm looking at are off a Pontiac G6 (3500 heads), i don't know what intake i'm gonna use yet though. depending on the intake, i might have to change of=ver to coil packs

 

i'm gonna have to go for a full rebuild on the 3.1. i found the crank needs more than just the journals polished. found a crack on the 3-4 rod journal, and i'm definitely not going to risk running it like that. so i'm gonna have to pick up a new 3.1 crank (preferably forged), and while i'm at it i'm gonna build the entire bottom end. for boost. i can't find any good heads for that will bolt up to the 3.1.

 

What about the 3100 heads with the 3400 intake?