Engine swap pulley problem

[PTmowerMech]

M# LGT2654
Product # 960450047
S# 061815A031116

Briggs 407777 0274 G5
A couple of issues here.

This engine has the smaller crank because it had the manual PTO. The rider it's on now, once had an electric PTO. Using the crank & deck pulley, the deck belt pulley rubs the drag links when I turn left or right. Since this is only a rider (never going to put a deck on it) I'm thinking I could grind the pulley down. Or better yet, find a pulley that doesn't drop down so far.
And preferably, one that's has a bigger ID for the drive belt. For a couple of reasons.
The belt that's on it seems to a tad on the loose side. It pops off when I press the clutch/brake all the way in. I could simply find a belt 1/2 shorter.
But the speed is slow. My thinking is an engine pulley with a larger ID (1/2" or so), would help make it go faster.

Seriously, with the lever at full speed, it's very slow.

 

[PTmowerMech]

 

[PTmowerMech]

Maybe replace it with something like this? With the set screw.

 

[PTmowerMech]

This works pretty good.
I do have a weird new noise coming from underneath. It sounds like someone is fumbling around in a plastic bucket. And the clutch/brake wiggles sometimes.

But, the mower is faster and the belt stays on.