this will be on a 305 with a stock bore or possibly .30 over i havent had it looked at yet. the heads will be the 113 Aluminum TPI vette heads, 58cc chamber, 1.94 1.5 valves. i have to use a composite gasket and the thickness is .041. the cylinders will be chamferd for to reduce valve shrouding. heres the deal: in order to get the same "burn" out of the aluminum heads as the irons i need raise the compression up to 10.50:1 stock is 9.5:1. how much do i need to plane the heads? do i have to deck the block? im planning on gettin forged pistons in case i use spray down the road. can i get pistons thatll raise the comp. thanks guys.

 

You do not need to "chamfer" the cylinders.
The area where the cylinder is closest to the valve is a very low flow area. Don't waste your time. If you want to improve the airflow into the chamber then work on the area right near the spark plug. This is a high flow area and responds well to deshrouding.
Get a garden hose and squirt some water through the intake port and watch the water as it leaves the port. You'll see what I mean.
Look at these CNC ported L-98 heads. You'll see whare they are reworked.

Use flat top pistons. Forged is a good idea for a Squeezed motor. get the deck height and quench area right before you worry about shaving the head.
With a .040" head gasket you want a final 0 deck height.
You'll have to get the pistons and measure them in the block
to know for sure how much decking will be required.
**** Approximate*******
Every .0065" shaved off the heads will remove 1 cc
**** Approximate***
on your motor with 5cc flat top pistons at "0 deck height",
and a .041" gasket I would shave the heads to 53cc's
(about .030") I would shave .025" off and then cc the chamber to check it first. Then you'll know what final cut is required to get the final cc you want.
Its all about detail and checking.

this will give you 10.45:1 compression.

 

just what im lookin for. thanks a lot man.