A small block 400 is a step too far. Even with "steam hole" heads, they had chronic overheating problems and the rod/stroke ratio was way wrong for good torque. Other than a few applications in big station wagons, motorhomes, and trailer towing pickups, it was a solution looking for a problem.
Jerry
Made good money in the early '80 at GM dealer on small block 400. They didn't seem to like being run 1 qrt low on oil under load, wipe out some rod bearings. I think part of the issue is more heat transfer to the oil than other small blocks. Replace many blown up 400 with "Target Master 350" due to they were cheaper than a short block to partial engine 400. Since the 400 is externally balanced, would replace crank damper & knock the balance weight off the flex plate.
