I have a question on pistons that I'm hoping someone may have also had. I just purchased a new piston set for my 1976 2.7 CIS 911s. The part # on the box is 911.103.949.01, this is the correct part. My issue is that the pistons are of the older style with a uniform dome at the top with notches for the valves (right piston in photo). This is the early style according to waynes rebuild book. The ones that I pulled off had a steep concave surface without notches for the valves which I understand is the CIS style (middle piston in photo). This is also the style that Wayne shows in the rebuild book for my engine year. I wonder if porsche superceded the CIS style pistons with the notched ones.
Anyone know for sure before I put them on?
Thanks,
Jesse
