I don't know if you have the heads yet. I have been looking at Brodix 15 degree 262 cc with the more common 40/60 valve lay out or the 287 ccc 40/60 I have Wisco customs piston in both my 434 and new 415 ci. The late model dirt trackers are all running 434 - 447 ci small blocks with heads like these so the pistons are availiableI started building my new engine!artyon: I will be replacing my 396 with a 434 inch SB with BMR 248cc 18 degree heads. Just curious who else is running a 18 degree setup?