That number doesn't match any I could find, you sure you've got it right? Drivers side of the block, just above where the transmission bolts up. They should be fairly large numbers. Be sure you clean all of the grease off because it can make one number look like another. If it's a 70's and early 80's vette, likely there is no difference between it and any other 350 of the time. The only engine you can tell if it is from a Corvette by the block casting number is the LT-5 which is also overhead cam, so it is obvious it is different. So, why even bother looking up the block casting number? Just put it in your car and if it goes good, it goes good. There is a pad on the front passenger side of the block just below where the head interfaces with the block, that will give you more information about where the block came from. Because of the 1 at the beggining of the number, this engine is most likely out of a late 80's GM car or truck or it is a goodwrench crate motor.