Been out of the hobby for 6 1/2 years. When did they quit making mac 67's? Do they still make parts? I've seen new cmb 67 HR's, is that the only current new 67 made now?
the problem with the MAC 67 is that the bore is smaller than the CMB 67. You can use a CMB 67 P/S in the MAC but it will put you over .67. the longer stroke was very good design but made it specific to the P/S used to make it a .67.