Magnum Heads

DionR said

I am running those same manifolds on my MP R/T heads and I had to get some plates cut to run them. The material around the port on the head was too small to seal the port in the manifold. I've seen OEM Magnum heads where there wouldn't be an issue, but I've also seen one's with the same configuration as my aftermarket ones that would be an issue. Just an FYI and warning.

Click to expand...

Glad you caught that.
Agree 100%!
I know some aftermarket along with the r/t do have less flange around the end ports.
I had bought some Summit shorty headers for my truck that I just put some aftermarket Magnums on 'not even gasket matched on the exh side'.. to find that there was only about .030 width of sealing surface at the lower corners. In fact...I had to weld up the bottoms of all header ports and the lower corners and file flat to make them seal up... I also die ground out all the welding that protruded into the port window they were .150 too small all around!!! ..and when I got done...it finally felt like I put headers on. Avoid summit headers. They are total ****. Just look them over with a mic and good header gaskets...they are garbage.
What a pain in the *** it was to fix them. I would have returned them if I hadn't already modified my down pipes to fit!

Bringing it back...
..So be careful which exh manifolds you use and with what casting heads.