2.2" pulley, getting bad belt slip at 4800rpm...
 

Of course, I have the oversized idler as well. At WOT, it pulls great until it gets around 4800-4900 rpm, then the belt starts slipping with decreased boost, and continues to slip until it shifts. Is there anything I need to look for to make it stop? It's kind of irritating. The only thing I can think of is possibly increased resistance caused by the washer I had to put behind it.

TWM, it has to be something along those lines. We're running the same setup, but my shifts are even higher than yours....and my redline, and I don't get any slip. I'd try a can of belt dressing first. That might give the gator a bit more grip. Clean the pulley path and belt with some orange/citrus first, rinse, dry, and belt dressing.

If that doesn't work, you really need to move forward with a permanent fix. We may have to do some really good comparison photos of our setups to help figure it out, and link Brian to the thread.

Between the 3 of us, we'll figger it out for sure.

Here's what I'm going to try here in about 3 hrs. I'll pull the pulley out a bit and put a set of calipers on it and get an out to out dimension. What other dimensions will help tell if it's the right size?

I had my stock pulley here at work until yesterday for comparison......but my boss took it home with him last night. He has a 95 SC Riviera. I don't think he's ready for the swap yet. You sold your stocker, right? Or do you have it to measure the ID?

I can get some calipers on my input shaft and measure my gap between the ND and the back face of the pulley if you need. Just let me know. Calipers are sitting here next to me, and the car is 50' out the door in the parking lot.

ND?

On my stock pulley, I have from the center of the belt track to the outside edge (SC side) is .762".

Measure the gap between the pulley face and SC Nosedrive if you can.

There's no room, unless I'm not understanding. With the washer behind it, there is about .127" to the housing, then, of course, the bushing part of the pulley goes inside.

BTW, this is the 2.2" that's on it now.

Just going on a slight hunch here, how can you tell from the outside if you have a 92/93 SC or a 94/95 SC??

The ribs on a 94/95 don't go all the way down to the base, and the driver's side back corner base is thicker than on a 94/95.