So picked up a 1983 Z28 recently and I was ''Told'' the engine was rebuilt. I know thats far from the truth. Also said it was a 4 bolt.

Pulled the numbers from the block and heads.

Block 3970010. Heads 3973487X. Intake is a Edelbrock SP2P and Carb is a Holley 6619-1.

So far from what I have gathered, its most likely is a 5.7. Yet the block was used in many other applications.

Heads can be 1.94/1.5 or 2.02/1.6. Alot of people say the X is for the bigger valves but I found some saying their X's had the smaller ones as well.

Intake is crap from what I have gathered. Carb is an emissions carb that is a 600cfm.


So what do I have here honestly? Something decent or what? This is my oldest engine I have had. The engine was abused to hell. Was running on 1qt of oil. Each header had 3 bolts missing causing a almost knocking sound leak. Spark Plugs gapped at .15 to .30. 2 Wires burned through.

I fixed all these problems and now runs and sounds pretty good. Havent had much time to drive it now due to not having insurance.

So my questions are obviously what I have said, decent engine to keep around? I know a decent upgrade would be swapping the intake to something else, Maybe a Performer RPM?

Any help welcomed, first Carb engine. Previous engines in my thirdgens were a 97 LT1 and a L05..

 

What it was when it left the factory and what it is now after 30 years ....
'010 is a 350 block; might be from a 370Hp LT1 Vette or a 165Hp truck (more likely )

Read
https://www.thirdgen.org/forums/post...12-post18.html
https://www.thirdgen.org/forums/post...90-post32.html
https://www.thirdgen.org/forums/post...44-post48.html

 

487x heads are no longer special, except to a few restoration guys. They are 76 cc, and they can have the 1.94 / 1.50" valves. Put them over dished pistons, you're wasting what little potential they have. At least they are less likely to crack than 624s. If you don't know what you have, I'd pull the heads. Measure the valves, look at the pistons, then reassemble with FelPro 1094 rubber-coated steel-shims unless the block has been zero-decked. For small valves and dished pistons, I'd use a Comp 12-305-2 cam and a Performer intake. NOT the RPM. That'd be for big valves and flat tops, with a Comp 12-239-3 cam. I can't abide mystery cams.