If you not familiar with them, the Gen II LT1's are special
. Basically a Small Block with different heads and intake. Some things I have learned the hard way:
Came in Corvettes, B-Body cars (Caprice, Roadmaster) and F-bodies (Camaro, Firebird) to remove engines: B-Body's can come out from the top like God intended. Satan designed the F-Bodies to come out from the bottom, unless you disassemble the ENTIRE engine first. Vettes look easy but no body in their right mind would ever let me wrenched on one.
Reverse Flow Cooling-designed to cool the heads first, then the block. I have seen some pictures of the cooling path, but to this day, I cannot comprehend it. Kinda like a Mopar torsion bar suspension. Just does not compute!
Heads-Aluminum on Vettes & F-Bodys got a little more HP, Iron on Caprices, Roadmasters, cops let them idle for days with no worry. Known for broken exhaust manifold bolts. Google it and wonder why GM uses torque-to-yield fasteners.
Intake-Has NO coolant flowing through it so no water leaks. Oil, however, seems to leak on regular intervals. Check the owner's manual, they may be part of the regular maintenance schedule. Gaskets are not a bad job in the B-bodies. Sucks in a major way on the F-bodies as the windshield comes half way over the engine. Mentally prepare for this. Throttle body blades like to coke up and stick. Buy lots of spray cleaner.
Water pump-another one of Satan's designs. driven off of the cam, there is no side load-so no bearing wear. But the steel drive connector will strip out and leave you and your wife stranded on the highway in 103 degree heat...while you wait for the AAA tow truck, decide on a visitation schedule for the kids. No matter how much you drain the system to replace it, there is always some that will pour down on the distributor.
Distributor-Optispark, Yes, having way more faith in the water pump then they should have, the design team moved it UNDER the water pump for packaging purposes. It sometimes gets a bad rap. Driven by a cam through the front timing cover. Early units were unvented and tended to fill with moisture and fail. later vented ones can be reliable as long as the water never needs to be removed. My T/A has 127,000 miles on it. It has even run when the front cover seal failed and it filled with oil. Cleaned it out and still going. Still an idiotic place for electronics.
Front timing cover-has three holes in it for the crank, water pump and the optispark. this is also three more places to leak oil. There are special tools to put these seals in, some have used a Sharpie body with some success. I bought the tool once my kid realized I was stealing her markers.
Plug wires-almost impossible to route without extensive removal of front drive. F-bodies are a little better since they run around the accessories. B-bodys go BEHIND the power steering pump. Have metric crow's foot wrench on hand and prepare for a Exxon Valdez sized mess. My garage is now an EPA Superfund site.
PCM-reliable and reflashable. Tuner-cat has the software but it is NOT windows based. If you failed MS-DOS in college, keep your sanity and pay someone to do it for you.
Thermostat - Just know it's different. do NOT try to use a regular SBC one to save some coin. If you do, it will overheat and again, strand you and your wife on the side of the road. Good thing is it gives you time to divide up your assets while you wait for your new friend and roommate, the AAA tow truck driver.
Performance - Mostly reliable with the above exceptions. good power and great torque. Not many mods out there and what is available, has an extremely unfavorable horsepower to cost ratio. Years ago I worked at YearOne and watched as the execs dumped tons of mods for little results. even after LT4 kits, cams, CAI, headers, exhaust and PCM programing, best they got was a couple of 100 HP for many thousands of dollars. Ultimately, if you want gobs of power, your have two choices: A. forced induction or B. LS swap.
I tended to beat up on them but their really good engines and still go like stink! (yeah, I own 2 of them. T/A and Caprice wagon with 215K) Given me plenty of smiles per mile. Not many places stock parts for them as they were made for only a few years. I can see that this was GM's last hoorah for the SBC. They really did all they could without a major design change. The LS successor is way better in power and cost, so you may want to think about that before jumping on this swap.
Good luck.