Jandro with the help of Pdude and Comp's tech that combination was well thought out.Pistons are 6cc valve relief and are .01 in the hole.I wonder what had happened to you since I hadn't heard back from ya.Haven't you fired that engine up yet?You will be fine with 93 octane fuel.The last engine I built had a 248 TFX solid with # 46 heads(74 vintage) that do not flow as well as Ken's(6X's)at low lift.And they propeled a stock bodied 74 GTO to 7.80's 1/8 mile with 170's 60 ft.What carb did you decide on?If you're not going to use the 850dp,contact me.You should easily beat your friend's 12.80's 1/4 time with the 355's/373's we discuss.Keep the initial timing 10-12 and total @ 34 @ 2800-3000 rpms and tune from there.If using MSD's ignition(HINT!,HINT!),use one light silver spring and one medium blue spring in the distributor.Shift points 5600-5800,or bring it to me for the complete break-in
