SOLVED!! Very low compression! Ran a compression test and SURPRISE, 105-110 PSI in each cylinder! Before you say "maybe the gauge was bad" I replaced the gauge with a calibrated gauge in the same range, same result! The engine has dished pistons. I didn't realize the impact the dished pistons would have. The engine is strong, but makes little torque, now I know why. The good news is that I've picked up an 89 5.0 roller with factory forged pistons!