I have a question about the 5xx577 blocks. Full disclosure; I have the (gasp) 5xx577 block for my 462 stroker motor. However, i am not sure which one 568577 or 500577. It is an XF block. 1977. I will know casting # in a few days.
OK, got that out of the way. As for my usage: I never planned on drag racing car. My friend who build it knows this. I love speed but it has never been about a time slip for me. I am a torque addict. Everything I have ever had (toy wise) has been a torque monster. It is only natural I wanted a firebird 400 .

I digress, To my point and for further discussion/debate from people who are smarter than me:

My research has left me with nothing but what appears to be 'folklore'. Internet cowboys who repeat what they have read and frankly there is very little out there on these blocks to substantiate the 'weak' claims. I don't say that in a sense of it isn't true but how weak when compare to say a chevy 350 2 bolt main or a sbc 400 are we talking. YES! it is weaker than it sibling (various other years of 400) but lets define weak.

For discussions sake:

http://www.pontiacstreetperformance.com/psp/racerGM.html this is a 1976 ... (brace yourselves) a 76 400 pushing some serious numbers and a drag race car at that. ?????

also: H.P.P. page 66 Rocky specifies the one year, 75 400 block,and its casting #500557 to avoid. Does this mean the 568577 will survive abuse?

Thoughts?