Have been gathering parts for my 491 BBC. Have pretty much found crank, rods, and block and heads. I looked through some catalogs and couldn't seem to find any pistons that should work.

.030 over 454 block 4.310 bore
4.25 crank
6.385 long rods

Heads are Holley 110 cc chamber Oval ports, a semi closed chamber. I was told I'd need closed chamber pistons.

Compression will be 10.5-11:1. I think that equates to about a 20-25 cc dome for about a .005 piston/deck combination.

Can anyone suggest a lead on pistons or will these have to be custom which is no big deal.


Also has anyone run 11:1-11.5:1 with aluminum heads with a BBC on pump gas with a 240-250@ solid flat or similar cam?

I was in the same boat last year, couldn't find a piston with the comp. ratio I wanted for my closed chamber heads. Ended up just having JE make me some.

Mike

Go to www.jepistons.com (http://www.jepistons.com) and see part number 142991 @ 18cc or 145376 @ 5cc. You'll need the matching ring set. I used the 142991. Quality piston without a doubt. Contact them with any concerns. I use the GMPP aluminum heads with a 110 cc chamber. ;)