I just picked up a 1967 small block motor. Chevy guy I bought it from said he took it out of his friends 67 Barracuda. They think its a 318. The casting number on the block is 2806030-273-4 cast on 4-7-67. The number stamped on the front of the block under the head is C 318. I thought the casting number on the side of the block had the motor displacement in the number which is 273 but on the front the stamped number is 318. What makes it more confusing is the motor has the 273 adjustable rockers with the correct heads and date codes. How can I find out what I have?