thats what I thought too... '67-'72 use the same mounts 6cyl- 454. just have to be placed correctly.

FWIW. my grandfather had a '67 GMC K25 ( 3/4 ton 4x4 ) with a 305E V6. when it blew in 1981, it sat till '82 when my dad and him swapped the 350 engine from his rusted up '73 blazer. they ither used the orig trucks mounts or the '73 blazer mounts. nothing was custom.. somthing tells me that '73-'87 mounts will also work and are more common in junkyards.. but the 6cyl mounts should work fine anyway