Vortec engine short block replacements

Are there any Vortec engine experts out there. I recently purchased a State Police Tahoe with 156K on the 5.7 engine. The car ran fine for about 2 months, then on a long trip, with a rather heavy incline, I started getting a screeching sound along with what sounds like a connecting rod noise. My question is, are any of the 91 to 95, 5.0 and 5.7 short blocks interchangeable with the Vortec, I have a 5.0 that runs perfect or I ahve access to a couple of 80's ish 5.7 blocks. Any help would be appreciated.