most hp from std block

Had an engine back in the 90's that dynoed at 580. Then we sprayed 175HP of nitrous on it. Lasted for several years. But, when it did let go it got ugly. Too much fuel and timing was the cause. Split cylinder wall on #6. So we tore it down to do a sleeve. Found the block was cracked from the main web into the cam.

If the block had had filler I think we could have been OK. It was a '70 casting date 360 with the stock 2 bolt caps.

Leon