[oz07]

'67 GTO ac,ps. Someone has changed to a later style timing cover but still have original ac,ps,alt bracket's but pulley's don't line up. I currently have crank pulley two groove 9786907 & 1 groove 9782704. Water pump pulley 196669. I can't seem to find these numbers to find out where to start and fix the issue. I want to get a set of the correct '67 pulleys and the pulleys that will make the later cover work until i get a chance to go back to original. Thanks in advance.

[toolin]

Ihave a full set of pulleys.
PM me.

[oz07]

bump

[Shadowjack]

Pulleys are always a big pain. Nothing really can be mixed because there were so many changes to the front of the engine from '67 to '71, when they stabilized. Luckily, the brackets at least are the same for '67 to '70 and again from '71-80. But you can't mix parts across the '70-'71 line.
In '67, with the stock 8-bolt water pump and the built-up six-bolt balancer, the balancer and pulleys were one assembly. Your numbers will never show on a parts list because they were never available separately, but if you have a 6-bolt hub, it likely will work. The problem, I think, will be that the later timing cover has the timing tab in the wrong place for the TDC mark on your balancer. The WP pulley you have is not a Pontiac part, which is why it will not line up. Throw it away.
In '68, they changed the balancer to the later one-piece type, with separately-available pulleys, but they kept the 8-bolt water pump. They also changed all the part numbers. I don't know how a '68 timing cover compares to the others as far as timing tabs.
In '69, they changed to a 11-bolt water pump and left the timing cover and balancer alone until '74 or '75. So far so good, except for a slight change to the upper alternator strap in '70, which will work on earlier cars, since the brackets and pulleys are the same.
There are two water pumps for '69, and lot of opinions about where you find them. One is about 4" from the gasket surface to the fan flange, the other is about 4-3/8" or so. Sometimes rebuilders are pretty casual about how far they press the shaft into the body, so it can vary a little, and make it rough to line up the belts.
The short pump needs a special WP pulley which is a little rare. As it happens, from personal experiance on a '69, I've found that a '67 WP pulley will work, being that they're a 4" pump as well.
Yearly change being a good idea, all brackets and pulleys were changed completely in '71, but they did keep those part numbers until the end of production.
In '75 or whatever, the balancer and the timing cover were changed to a small hub and separate timing tab.
So, as to your problem, if you ever find a full set of parts, grab them because it's really tough to find all the pulleys, balancer, and brackets together.
Clear as mud?

[oz07]

Thanks Shawdow - It does help somewhat. I really appreciate the info you shared.