magnum manifolds

There were two sizes of spigot outlets on magnum manifolds. The early was 2-1/8 and the later was 1-7/8. The common modification concerning magnum manifolds (with an a body anyway) is using a right hand manifold and boring the 2-1/8 outlet to 2-1/4 inches. I’m a little fuzzy on the stock exhaust pipe size for which manifolds at the moment, but I’m pretty sure that the modified early manifold makes use of a 2-1/4 inch pipe and the later manifold uses 2 inch pipe stock.