A 327 / 275 package in 1967 would have used a Saginaw 4-speed. Under 300HP was considered "light duty" and got the Saginaw, power above that got the Muncie. A very small number of Muncie Chevy IIs in '67.
I bring this up in case there is a transmission mixup at play, as certain parts are different and you could run into trouble. Happens frequently. Or alternatively you have an L79 which would be fantastic.
As for the clutch, the GM docs indicate no heavy duty clutch option for your setup. The 327 is listed as using the 10.4" diaphragm clutch with "bent" fingers and 10 coil springs. The smaller ones were 9.12" & 10".