Ok I've just pulled apart my L98 and am suprised to find that my piston to deck diminsion is about 0.050"! (Federal Mogal flat tops) I was hoping for about 0.025" and am/was planning to use a Felpro 0.015 shim gasket for a 0.040" quench. Now it looks like I'm at 0.065" unless I get the block decked. Block decking wasn't in my plan for now as I am planning to go 383 at a later time. I am hoping to get my DCR to 8.2 or so and am concerned about detonation. My questions are:
1) What will be the effect(s) of running a 0.065" quench?
2) Will I have a problem with detonation with high DCR and this large quench?
Any imput will be greatly appreciated.

 

Is this is a stock L98 with .050" deck height? How did you measure it?
If those are rebuilder pistons then they usually add .020" to the stock .025" deck height, so I think you're in the right ballpark.

What's the SCR on the engine? .065" quench is high, but if you've only got 9.5:1 CR or so then I wouldn't lose sleep over it.

 

Yes, it's a stock L98 with the exception of the pistons. (and cam, intake headers etc) I measured it with a dial calipers (depth end) and then with my dial indicator dragged from the block to the piston at TDC. Not the most accurate way- but it's close. Yes, they're rebuilder, flat top pistons. I thought I was at 9.7 SCR but will have to recalculate with this new deck height. My intent is to push the compression to the max with 93 octane. With the original target of 0.040" quench, I should have ended up at around 10.2 SCR and 8.2 DCR. Now I'm going to re-figure. Probably tonight when I should be sleeping...

 

i'm running a .064" quench on my motor.. 10.65:1, 385ci and polished chamber AL heads.. running healthy on 92 octane.. and i rev her up to 6600.. limiter on 6700.. running 16* initial and 39* total timing.. been working great so far besides the sleeve on the #3 cylinder is warped and leaking compression..

 

Recalculated compression. 9.19 ug! DCR is well under 8. Going to step back and think about this one. I can get SCR up to mid 9's and DCR to about 8 with some milling but will still be stuck with the 0.065" quench. I just don't like it cause if I go 383 later my CR's would be WAY high with the milled heads. Maybe this IS the time to go 383. Sure cures alot of problems. Either way I will still have to get the block decked. Or will I? If the pistons for the 383 would put the deck height back up to 0.025" I could acheive 0.040" quench with a shim gasket. I could easilly get into the 10 SCR range with DCR in the low 8's. Plus there's no better way to increase power than with cubic inches! Yes????

 

i would deck it to 9.000 (factory is 9.025) and use a shim gasket.. dont mill the heads unless you absolutely know what you are going to buy..