[Keithc8]

Detination or pre-ignition is very hard on an engine. You may have the fuel igniting before it is suppose to or not igniting properly which will hammer the bearings, try to turn the crank backwards or crack the block. This is more commen on engines that have forced induction because of the air going into engine and the engine not being properly tuned. The 351W blocks are prone to crack in the mains with to much power or detination. I do not like to run them much above 600HP. The girdle will help a little on the bottem end. The weight of the parts used, compression, crank stroke and rpm will all affect the life of the block. The early blocks seem to be stronger than the later blocks. Good luck, Keith Craft