[QUOTE=StreetShark]Hey all, I have a 68 with an aftermarket 350SB.  Does the vin tell me what the original engine was?  If not how can I find out?  I like the 350 but would be nice to at least know.[/QUOTE]

Sorry, but the vin will not give you that info. Your only hope is documentation. Tank sticker, or possibly some paperwork that have come with the car.

I plan on doing some suspension work soon, can I get to the tank sticker when I pull the rear suspension apart?

[QUOTE=StreetShark]I plan on doing some suspension work soon, can I get to the tank sticker when I pull the rear suspension apart?[/QUOTE]

Typically, they are on top of the tank, on the right (driver)  side. You may be able tp pull back the filler neck boot and look in with a flashlight. If you can see it, you need to drop the tank to properly remove it. It's just a piece of cheap paper glued directly to the tank and in all likelihood, it won't be in very good condotion if it's even still there.