I've built about 100 + 400 smallblocks in my time I used to own a chevy high performance shop. to say the least they are the easiest to make large toque and h.p from.I dynoed a block that made 522 hp 518 ft pd of torque all at under 6200 rpm at the price of less then 5000 dollars.in a 4000 pd car I ran 12'0s at 114 mph on pump fuel and ran 12 laps back to back one time to see consistency.(the brakes started to fail bad!!!!) don't recommend. the real reason the 400 gets shot down for getting hot is you must have the proper cooling system and if you want to spend the extra try Evans cooling it doesn't boil till 350 + degrees. because the cylinders are symised you get flash points where the cylinders join. Evan's won't try to run away with its high boiling point.