I built a standard bore 360 about 5 years ago that went 12.40's all day long in 90 degree heat with a stock convertor and 3.91's, stock street tires and exhaust. It can be done very easy. I ran circles aroung another A-body with a 360 magnum that had tons done to it and was dynoed at 424 hp and he had a 2800 convertor and 4.30's. All I had was a 360 with a set of 273 rods with a set of kieth black 10 to 1 pistons. Had a 508 purple shaft, adjustable rockers stock heads. Single plane Edlebrock Torquer 2 and a 750 double pumper. All the tuning I did was on the carb with huge jets and total timing was 34 degrees. The more fuel and less timing the faster it ran. I have lots of video to prove it. Trust me you can get 500 hp with a pretty stock bottom end out of a 360. Just remember it's not a chebby. I spent less than 2k building it and it's still together today. I have pushed it many times to 7300-7400 hundred with no problems at all.