[bmcgc]

I installed a new WP today.

In all my reading on WP replacement, I have not seen this addressed.

When I attempted to install the pulley, I found that the snout on the new WP has a bigger diameter than the old WP.

Old: 5/8 dia New 3/4 dia

I had painted the new WP and was in way to deep to stop.

I also added a fan clutch, the new clutch matched the new WP.

So I drilled out the hole in my 2 groove WP pulley to 3/4 with a step bit.

The four bolts went in without any trouble, so hopefully the WP pulley is balanced and will not vibrate.

Did I just buy the wrong pump or is there another issue?

My car is an early 65, 14 Aug 64 scheduled build date. It does have a cast WP with backing plate.

 

[awhtx]

I have never seen a SBF water pump with anything other than a 5/8" snout. But my experience is pretty well limited to V-belts so maybe the later serpentine 302/5.0 used a pump with a 3/4" snout.

 

[bmcgc]

Thats a good guess, although those would be reverse rotation pumps.

Its a GMB 125-1420

The application guide says 1966 289

It has a lifetime warranty, so if it ever gives up, the next one is free.