During the 1-2 shift, there's a nasty squeal that comes from the engine, particularly during hard acceleration. I think it's the belt. What can I do about it?

This is a fairly common problem with LT1's making a lot of HP (or even some stock LT1s). Remove the old belt by using a box end wrench to loosen the idler pulley: it is either 1/2" (my car, from experience) or 9/16" (from the Helms manual). You don't actually loosen anything, the pulley is spring loaded and will take tension off of the belt. Then clean each of the pulleys using alcohol or brake parts cleaner. Make sure you don't use something that will leave a residue. Cotton swabs or a toothbrush work well for getting in the grooves on the pulleys. Next, you might want to use some fine grit sandpaper across the pulleys perpendicular to their rotation to rough up the surface just a little bit. Reclean with the brake parts cleaner to remove any sanding gunk. Next, install a brand new belt, routing it in the same manner as the one you took off. A couple shots of belt dressing will finish the job.  more