can anyone tell me what is different between a 366 big block truck motor and a 396

366 is a tall deck but with a small bore.

can they be swapped in to a camaro and be a decent motor for street?

Well, you can, but you will have the same if not more hood fitment problems.

PLUS, you'll be stuck with having to use parts for TALL DECK engines only (to include intake, distributor, pistons).

Other than that its the same as any other BBC......

the reason i ask is that we have a 366 in a truck at work that runs like brand new and has only about 60,000 original miles. it was used to move mobile homes before we got it. it has hei . from performance stand point will it run good in a car? i have 77 i want to get big block for:D

If you can get the 366 for cheap, strip the 4-bolt main caps and steel crank, then scrap the rest. ANY 350 will outrun it. It's a very small bore block (3.935, a 350 is 4.000) with 3.76 stroke. Bore is very restrictive on breathing and there's not really anything you can do to help it. I tore one down a couple of years ago and was in for the surprise of my life when I found that I could remove pistons thru the bottom due to the big block's bore spacing and the 366's small pistons. It was built as an economy grunt engine for applications that took the durability of a big block.

thanks for the advice just thought that might work out lol didnt think i was that lucky lol