I have a set of new 84 cc Edelbrock RPM heads I planned on using on my 400 stroker build. My engine builder had planned on using flat top pistons but told me today that he found out that in order to use flat tops, the heads need to be milled down to about 72 cc in order to get the compression to around 10.8. Otherwise the compression will only be about mid 9's. The other option he said is to use dish pistons if I don't want to get the heads milled but he favors flat tops over dished so I think he would rather I have the heads milled. I am no engine expert so I would like to know if this sounds right and would also appreciate any input on this subject. Thanks.