EQ or magnum heads with Manifolds

Im looking to run either my stock 73 318 manifolds (for now) or swap to a set of 71-73 340 manifolds. Im trying to keep the car stock looking. Obviously magnum truck manifolds fit.

Well, I have test fit magnum exhaust manifolds on my 65 273 and my 87 318, had to grind the head a bit on the 87 where the rear most air injection port is and needed to plug the air injection ports, but they fit. I'd venture to say they'd fit the other way as long as you do not have exhaust manifolds with air injection ports. since those will not be covered.

I've been running early 340 manifolds on stock magnum heads for a few thousand miles with no problems. The top and both sides of the LA ports are almost the same as the Magnum. Biggest difference is the port floor is raised significantly on the Magnum. When you mate the 2 together, you will see there is only about 1/8" of common sealing area at the floor of the port. This can lead to leaks at the bottom of the ports. If you have any trouble you can use Remflex exhaust gaskets, they will seal between the 2.

Thanks Scott. I knew there was an issue with the port floor being lower, Wasnt sure if it caused a leak.