You'd have to change EVERYTHING in front of the harmonic balancer
The long water pump came out in '69, which means all the original pulleys, brackets and accesssory mounts will have to be changed. The alternator will be moved to the right side of the engine and that means major rewiring. You'd also have to change the fan shroud and fan spacer or fan. Do it right and get the short pump stuff
. For my part, nothing is uglier than a '67-'68 Camaro engine compartment with '69 accesssory drives. No slam on '69s
Keep 'em original
.