[tccrab]

LT1, likely plenty. check your local Chevy dealer, or pretty much any restoration shop.
LT5, uhh...nope.
Used to be a guy just across the border in Washington, but he evaporated long ago.
There are a small handful of LT5 pros out there, Marc Haibec, Cory Henderson, Bill Budreau, Graham Behan, to name a few.

Good luck.

Crabs