67 250 power steering conversion help

[NC67Chev]

So, I've got my hands on a complete set-up to convert my 67 truck with a 250 I6 to power steering. Also, I've got a grip on what needs to be accomplished regarding the mounting of the gear box. Anyway, yesterday afternoon I thought I would go ahead and change the water pump pulley to the new double groove pulley that I got with my set-up. The stock single pulley that I took off of my truck (p/n 3788472CG) measures approximately 7 1/16 inches. The new double groove pulley (p/n 3995646AH) measures approximately 5 3/4 inches. Also, the original single groove pulley is more rounded on the mounting surface (there is a fitted spacer that goes between the pulley and the water pump). The new double groove pulley is larger in diameter and is more flat. When I put the new pulley on, it seems to fit nicely and seems to line up well with the crank pulley. By the way, the donor power steering set-up came off of a '72 Nova. Because of the difference in the pulley diameters, I thought better of it and put the original one back on for now. So, after all of that, here are my questions: 1) Is this sounding familiar to anybody that has previously done this conversion? 2) Does it make any difference if the new pulley is smaller in diameter? Other than the obvious that I will need to get a shorter belt. 3) I'm assuming a smaller pulley will mean that the water pump will be turning a little faster. Is this correct? Is this significant in any way?

These might be very silly questions, but I don't want to make a mess out of my truck.

Thanks everybody!