Engine Codes got me stumped

I can't identify my engine. I just bought a 74 chevy truck that had a (i think) 454 dropped in it. It keeps tearing up the starter and I think I am getting the wrong one. All the numbering I can find is 4308 punched in the front of the block and "PASS", "HI PERF" on the driverside near bell housing. I also found "GM" "00NV1" on the back driverside above the bell housing, Any help? Please

chucky there should be some casting numbers on back of that block get these numbers and I believe we can figure just exactly what you have. But I personaly think you need to put the starter brace on the back they make 2 types,then check your shiming. This should be eighth inch gap between starter shaft and flywheel. good luke wjr