Porting BB heads

If you plan on taking on this job, I advise you do ALOT of reading, & maybe practice on a junk BB head 1st., I took on this job on a set of 906s, before anything i did, my machinest did a 30 deg. backcut on the valves with a 3 angle VJ, I used a new set of stainless "stock size" valves, Your going to spend alot of hours i'll say that, is it worth it, just depends, I'll never do it again, after i did mine, they flowed 268/199 @ around 550 lift. Forget the MP templates, you can go past them, at least i did, either way you go, have fun with it, I used high speed cutters.