'89 C1500 in Oregon

Interesting. I checked the member map and there isn't anyone from the NW? I joined recently to help collect information for the upcoming swap I have planned. I'm the original owner of an '89 RCLB, 305/5spd C1500. Body is clean and straight. The driveline has ~100k on it. The odometer quit around 83k. I've wondered what to do with the truck. I came up with the idea of an LS1/T56 swap. I'd like to get a classic muscle car, but probably not ready to drop $20-30k.
I came across this site and have been hanging around the LSx swap forum. I've learned quite a bit from the guys there. The guy that's going to help me recently came across a 2000 5.7 LS1/T56 from a 70k mile Firebird.
After the engine/trans, I'll probably need to change the gears since it has 3.08. I'm considering a 3.73 instead of the stock 3.42 that was in the Firebird. Anyone know if the rear end from the Firebird would bolt swap in for the stock 10 bolt so I could get disc brakes too?
thanks for your time.
-gl18rider