corvette 427 engine

I recently acquired a 427 chevy from a customer. It was a her late husbands and was building the motor to race. Ran the numbers and its a 66 Corvette 427. Block #'s 3869942, TOI27IP and 6113138 4 bolt main block. It's a mystery motor, aluminum rods, crank unknown and cam is in but also unknown. Cast in heads say HI PERF, GM 3T and E17 71. Was planning on keeping the motor but have decided to sell it to help buy a 72 im looking at. Was wondering if you guys could help me find the value or interested in the motor. Thank you.