What diameter is the pulley you currently have, and what size is the fanbelt?
When they changed pulley sizes, they also changed the belt size, which also affects the balancer.
The pump you have is a shortened one for 55-62.
I believe the Patricks kit comes with the larger diameter pulley and smaller fan belt like what you would expect to see on a 55-62 engine, but that doesn't mean you couldn't adapt the earlier stuff, should you need to. Just check with Patricks first.
There is also an adapter plate somebody is selling on Ebay to use the 53-54 type pump on the 55-62 block for about $40 should you want to run the larger belt and not have to use modified "wear" parts (the pump).
