Everybody slow down and read the questions before answering. I’ve read the answers and some are wrong.

Have to tell you that 1967 BB mopars With 4bbl are studs and nuts. Owned multi-dozens of these cars.

Friend bought a 67 GTX new and still owns it, very original car That is a great reference. Studs and nuts.

I know 1970 and 1971 are bolts only

I feel they changed to bolts in 1970 when the chokes and intakes changed and they started using the think carburetor base gaskets.

Same intake Manifold 1967-1969. Same hardware?