engine block

we got an 81 monte carlo with a 350. The engine was changed and we are looking for performance parts and its hard because the engine can not be idenified.
the only number we can find is above the water pump V0806sfd. Can I get help tring to find out about this engine. I believe its between 1987 and 1995.
If there is any links or ways of finding out please help
thank you

On the back of the block where the trans bolts to it on the drivers side there is a casting number. www.mortec.com will tell you what every casting number means. If you can obtain that casting # you will have it made in the shade my friend.