They are 23 spline A833 4-speeds made by the New Process company. They are the pretty much the same as B-Body transmissions except for the tailshaft and output shaft lengths. There were two part numbers, the 67-68 is 2892042 and the 69 is 3410608, I do not know the differences. BTW, these part numbers are the same for 273, 318, 340 and 383 trans. The 67 273 had it's own part number.