Exhaust System

I am doing a ground up resto on a 74 850 Interstate. I believe it is a MII. A friend has offered me an exhaust system at a good price. It was unused in his MIII Roadster project when he upgraded to a 1 1/2 in system. In checking the part # of the pipes, 065257, I find that is a MIII pipe and the part # for a 74 850 is different. Will the MIII pipe work on a 74? Is the exhaust port different? I would like to use this system if possible.

The MkIII pipes used a belled end at the head. This requires using the spherical insert (P/N 065259) in the head and the corresponding MkIII collets (P/N 065360) in the exhaust nuts. This set up does provide less strain on the head fitting as it is not necessary to "tweak" the pipes to mount the mufflers and cross-over and still maintain a parallel relationship between the head port surface and the flat exhaust flange. The end result is they seem to stay tight with less torque on the exhaust rose.

This style is also available without the cross-over from some suppliers.