79 L48 pistons

[jwbreeze]

I recently bought a 79 coupe with the L48 package. It's bone stock with 56K miles. I'm planning some engine mods and would like to know if this thing has flat top pistons or dished. I've heard that all corvettes have flat top pistons and that the difference in comp. ratio between the L48 and L82 is due to different heads. Can anyone enlighten me on this issue?

 

[cleon]

I also have a 1979 L 48. I have done some mods and have had the heads off. The pistons
in my L-48 are flat top. I think the L-48 L-82 difference in in the heads.

 

[JohnZ]

I also have a 1979 L 48. I have done some mods and have had the heads off. The pistons
in my L-48 are flat top. I think the L-48 L-82 difference in in the heads.

Nope. All '78-'82 Corvettes (except the '80 California 305) used the same cylinder heads (casting #462624).

 

[cleon]

Nope. All '78-'82 Corvettes (except the '80 California 305) used the same cylinder heads (casting #462624).

Thanks for the info. Then the only way to increas the comp. is with different pistons?

 

[Vette79]

Thanks for the info. Then the only way to increas the comp. is with different pistons?

I would replace the heads first before replacing the pistons if you are looking for increased comp. John, the valves on the L82 heads are different, right? The L82 has a different cam, aluminum intake and aluminum valve covers.

 

[73shark]

What year did the L-82s start coming w/ an aluminum intake manifold?

 

[JohnZ]

What year did the L-82s start coming w/ an aluminum intake manifold?

'78-'80 L-82's (and '80-'81 base engines) had aluminum intake manifolds.

 

[73shark]

Was there any difference between the aluminum ones and the cast iron ones?

 

[JohnZ]

Was there any difference between the aluminum ones and the cast iron ones?

The L-82 aluminum intakes had less-restrictive and more free-flowing port runner design than the base engine cast iron intakes.