318 exhaust manifolds on a 360

Here are the pics I promised. The first and second pic are of the '76 318 manifold I have then the 3rd and 4th pics are of my '69 Barracuda 318 manifold. The '76 small block manifold is close to 1 3/4" while the stock '69 Cuda is a hair less than 1 3/4" ( earlier I had said 1 7/8", I only wish). Anyway, this shows one reason why you are very limited on power output on a 318/360. With manifold exit holes of 1 3/4" or less the poor engine can't breath (exhale)....no matter how big your pipes are!!!!
The small block manifolds I'm selling are just a little under 2 1/4". If you run these manifolds with 2 1/4 exhaust pipes (or larger) your small block can breath pretty good without the hassle and expense of the headers.
Of course you do have to find a 340 driver's side like I did and you have to have the 360 head exhaust surface (the one with the provision for the smog ports) or 302 casting heads. If you're not sure about the smog port thing....if you look at the 1st or second to the last pic you can see the extra metal (machined surface) just below the ports on the '76 manifold, this machined area is missing on the older manifold. This is also the area that so many members have trouble getting the larger 360 manifold ports to seal because the old 318 heads don't have enough machined surface below the port to seal against the larger 360 manifolds.


More pics later.........
Treblig