Have a set of emi thunders with standard risers on my 21 laveycraft 454 with a 177. Have some edelbrock heads waiting but curious if anyone has input on how much cam is to much for these manifolds. I have a 01#456-8 comp cam but Im pretty sure ill get reversion. Any input would be great. Thanks.

I have those too and I bought the longer stainless risers. The website says that their "stock" setup is not to be used with aftermarket camshafts.

Yah that might be the way I need to go and have them put a 02 bung in the them.

Not sure it would matter with your setup but I wish I told them on which side of the riser to install the 02 bung.