I just finished installing the Edelbrock RPM package in my 68 Camaro 350. I installed an old set of Dynomax headers that I had and used a Mr Gasket Ultra Seal header gasket. I blew this gasket out shortly after breaking in the engine between 4 and 6 exhaust ports. I know Edelbrock recommends a 1-3/4" header for this application, but I really don't want to go that big. When header size is stated, is it ID or OD measurements?
Is anybody here currently using Dynomax headers with this setup? If so do you know the part# of the headers and gasket being used?
Thanks for any help.