I'VE PURCHASED A 1970 SKYLARK ENGINE IDENTIFICATION #1382201 L. I WAS TOLD IT WAS A 350. BUT EVERY PART I'VE BOUGHT TO THIS POINT FOR A 350 BUICK 1970 SKYLARK DOESN'T FIT. HELP

Shawn, have a look at the Big Block Casting Numbers section on this site under the Shop tab. Here it indicates the engine is a 1970 455.

The engine producton code number is stamped into the block and is a better identifier than the casting numbers. These numbers are also in the Shop section under Identify Your Buick Engine.

Shawn,
My Automotive Rebuilders's software shows that casting number as a 350. What parts have you purchased that don't fit ??

is that all you can tell me? why does it have a front distributor? Why is it bigger than the 72 350 thats in my truck? Could it be a 350/401 big block like someone else suggested? Is it rare?
in answer to your question the oil filter for a 1970 skylark custom with a 350 did not fit.

Thank you so much for your help. I would still like to know why it has 350 stamped on the underside of the block.Can i match a 700r4 tranny to it?What are some companies that make a lot of aftermarket parts for this motor? I also really need body mounts and neither year one or jc whitney has them.
Im sorry for the game of 20 questions but this is my first restoration project (hopefully the first of many)and all your info is appreciated.

Shawn,
Let's go right to basics here, the 350 motor in your truck is probably your basic garden variety small block chev, which is the smallest of the four different small block castings created by GM.
What you should have is a small block Buick 350. However, since you say that parts bought for a Buick 350 do not fit, let's try another approach,
What color is the block? Buick and Chev were similar in color, Buick is more reddish orange than Chevys orange. Pontiac 350 should be a light silver blue color, and Olds 350s were often black. Confusing? sure is!! It's possible that in the 32 years since your car was built, someone has replaced the factory original motor with who knows what!!! If it is a 401 or 425 nailhead the valve covers will sit parallel to the ground, not at an angle like your Chev 350. Still with me?? good, for coloring, a nailhead should be light blue.
I think that an adaptor may be required to match a 700R4 trans to your motor, can't say for sure until you positively ID the motor. Perhaps someone else on this board can answer that better than me. If it is in fact a 455 Buick motor the body tag and/or VIN should provide an engine code to confirm, hey sometimes people have been known to give inaccurate/incorrect/or misleading info to sell a car, especially with gas prices so high!!
Good Luck,
Tom