when I bought my FFHP forged LS6 347 everything of course was brand new

So, I need to know if my pistons still come out of the hole .006 like stock, I need to know what to change on the bore so that the calculations come out correctly to a 347...is there anything else I need to change so I can get my DCR correctly?

I'm using pianoprodigys DCR calc, awsome work by him.

stock crank, callies LS1 rods, diamond forged pistons...

 

you need to measure how much the pistons come out of the hole

 

see, that's kinda hard right now...it's my DD. I guess I need to know what the typical messurement is for the piston. Pretty sure the extra 1ci is coming from the bore...wish FFHP was still open so I could ask them everything I need to know.

 

Piston will come out differently than stock. different pistons and rod length. It also matters if block has been decked.
Like on my 370 pistons are .010 out.
When I calulated yours with the 228R +4 and 64cc chambers and .040 gasket, I used .005 (good medium) and your DCR came to ~ 8.45