318 exhaust manifolds on a 360

I have a '69 Barracuda w/power steering. 318 with 302 casting heads. 318 manifolds don't seal well because the ports are much smaller, see pics!! I'm using a 340 driver's side manifold and a 92-93 Mag truck 360 manifold on the passenger's side. the large port 360 mag truck manifolds are cheap $40-$60 on ebay and the flow real good. The exit port on the 360 manifold is only 1/32" smaller than the exit port of the 340 manifold....for $50 that's a pretty cheap solution!!!!

You can see the small 318 manifold gasket compared to the 360 gasket. I painted the 318 gasket blue so you can see how much of the 318 gasket falls inside the 360 gasket port. The 360 manifold almost swallows the 318 gasket and this is why you will have sealing issues. You can even see a little daylight at the bottom of the port (in the corners).

Treblig