Agreed with everyone above. You're killing yourself looking for a motor with a TPI already on it, when you'll need to pull the tpi off anyway. Old Multec injectors are notorious for taking a dump, especially when sitting for long periods (IE taken out of a car or sitting in a wreck).
If it was me, I'd look for an 87-95 truck 350. This way you get a 4 bolt block in the swap, instead of the 2 bolt crap that comes in every stock TPI motor.
Next I'd order up some new intake base gaskets.
Then injectors from FIC
http://www.corvetteinjectors.com/sho...p?productid=23 complete with the runner gaskets and new O-rings.
Then you need a prom for the new injectors/350.
http://fastchip.com/ or
http://www.tpis.com/pages/efi
Then lastly, you may want to do headers at the same time. I wouldn't waste my time bolting crusty manifolds back on to your new motor.
Also while you're at it, if you don't want the motor to look old, degrease it (Brakleen), and tape it off, and then hit it with some high temp engine enamel. Take the TPI off, and have it hot tanked, or just degrease it and maybe powder coat it. Better yet, swap on a Holley (Weiand) Stealth Ram while you're doing all the work (if you have extra $)
http://www.summitracing.com/parts/WND-7540/
The chip and injectors are the key. If you don't make sure those jive, the motor will hate you.
Things I would do while it's out: Oil pan gasket, Timing cover gaskets, valve cover gaskets, maybe a new oil pump. Degrease/paint the engine bay. Obvious things like plugs/wires. Lower temp fan switch.
Hope this helps.