Just a question....Didn't the sprint car guys used to use the factory blocks years ago? I know they are weak but when I was a kid the sprint cars were running 406 -410 ci and I know the top teams had aftermarket blocks but I mean the more local type racers that still ran well. I am speaking of early to mid 80's. Like I said just asking cause I know there are several options NOW for an affordable aftermarket block but what was around back then?