Does anyone here know what the stock cc`s on the L98 heads are??

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88GTA 5.7(under construction) ATI Procharger,58mmTB,ported plenum,SLP runners,Edelbrock HI-FLO base.ported heads,1.5RR,210/220/480 compcam,AFPR,SLP1 3/4 headers,3.70 gears,Eibach drag launch,Lakewood LCA`s, Nitto drag radials.

 

L98 AL heads are 58cc on the Vette.

 

The iron heads have 64 cc chambers. In the past board members have measured and validated that number. Actual measurements vary 1-2 cc (usually on the high side) due to production tolerances

 

Thanks for the help guys.

 

Also, I have contacted GM and they have confirmed that Iron Head L98s had 64 cc combustion chambers. So its official.

 

What is the dish on the piston and the stock compression ratio?

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87 Formula 350 14.61@94.07
98 Z28 1LE 13.15@107.59

 

Stock compression ratio on a L98 is 9.3 : 1

 

incorrect on the compression ratio's for 91-92. The correct compression ratio for 91-92 B2L (L98) is 9.75:1.

GM used less of a dish and lighter weight cast pistons for 91-92.

 

What kind of pistons do the '87 L98's have?

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87 Formula 350 14.61@94.07
98 Z28 1LE 13.15@107.59

 

Blak92 is correct about the 9.75:1 compression ratio on B2L L98s for 91-92. I have had this confirmed by GM (and my 1991 GM Shop Manual) too. I believe 90s were 9.5:1 also, though I have not confirmed this with GM and I don't have a 1990 GM Shop Manual.