I have a 350 engine in my 66 c10. After doing some acrobatics inside my engine bay, I've found that the block number is a 3970010 and it appears to have a year of 1976. Doing some research on it I get the idea this is most likely one of the lower (sub-200) hp factory engines, but the suffix codes on the front of the block are gone.

The previous owner has dropped an edelbrock intake and 4 bbl carb on it, but it still feels a little sluggish. It still has the old delco-remy distributor and some pretty generic-looking plug wires. What are my best options for getting this guy up into a respectable hp range (250-300)? Is it going to take a bottom to top rebuild to get any performance out of this engine?

Truck Shots:

http://s886.photobucket.com/albums/ac70/1965Stepside/Truck%20-%20New%20Purchase/