'67 L-79 water pump pulley question

[R N.]

My '67 L-79 w/o AIR (smog), P/S or A/C uses a two groove (deep) pulley on the water pump. I've read in many sources that there is a support disk that mounts on the inside of the pulley and between the water pump flange.

I would just like to know if this is correct because I've also read that it is not for my application.

What's correct?

Thanks everyone.

[Peter J.]

Re: '67 L-79 water pump pulley question

I am using one of the disks you are refering to on my 66 L-79 because the pump I bought from Paul at Goat hill had the flange pressed on to far and the pulley and body of water pump had just made contact. The pulley reinforcement disk moved it out just enough to clear and hasn't caused any problems.
I got the idea because I saw one of these disks in a catalog that referred to them in a GM service bulletin about pulley failure. I don't think they came off the assembly line but were put on in dealerships, but I could be wrong.
Pete

[Joe R.]

Re: '67 L-79 water pump pulley question

The part number for the "reinforcement" disk is 3720616. It appears in the 1967 AIM as item #9 in UPC 6, A3 for the base engine. In that drawing it appears to be placed between the water pump flange and the pulley.

According to Noland Adams' C2 book on page 358, a service bulletin was issued by GM in 1966, stating that there had been some pulley failures on 327/350 L79 engines and that the "reinforcement" should be added between the pulley and the fan.

So, it's not clear to me which side of the pulley the reinforcement should be placed, but I would expect it to provide better reinforcement for the pulley if placed on the inside.

[R N.]

Thank you Peter & Joe...

Thank you Peter & Joe...