[cooke]

Ignorance is bliss.........I guess. This topic is making me sick. So basically what you guys are saying here is that; as far as 455's go, the '70 - '74 are the strongest and '75 - '76 are okay for mild applications. And just do a visual inspection on "webbing" in the early years; especially when considering a 4-bolt conversion. I currently have one right now (455) that is not drilled for 4-bolt caps; but I believe it is older than a '75. I haven't checked the date code yet. Wouldn't the splayed caps be a wiser choice assuming there is adaquate material? At this time I just can't swing an aftermarket block.
What's crazy is; a few years ago we built a '75 455 out of a low mileage wagon. It had factory 2-bolt mains, Eagle rods, stock crank,flat-tappet cam, #62's, 1050 dominator, etc. All motor. It was in a '71 Firebird that had a race weight of 3680 lbs . It went a best of 10.73 @ 126 mph and a typically went low 10.80's most of the time. Never did come apart. The car was subjected to some fairly long "jaunts" on the street. The motor sold and went to Marty Parker (East Texas) and as far as I know; is still going fine. I was never aware of all of the weak "short-comings" that the late model blocks had.