Cheap Corvettes are weird in endurance racing, for some reason. They just never seem to do that well. Maybe it's that they invite people to drive them past their mechanical limits? I don't know. There were two C4s at CMP for the 24, and, I believe one finished the race, and the other almost did, but mechanical troubles sidelined them to the point that they got beat by a Volvo 850, a Buick Century, and a Kia Sephia.Strangely, all of them were from the mid-90s, and the Volvo ran into a transmission problem partway through the race that basically limited them to 60mph. So, yeah, weirdly, you're likely better off in a 'regular' sedan than you are in a Corvette. I'm sure others can pontificate further on why.
The problems with a 350 small block, or any small block Chevy, really, is that they don't like to rev. They last forever and ever on the street because they spend the overwhelming majority of their time below 3k rpm, and many even lower than that. When you take them on track and start revving them to 6k rpm at every shift, well, they don't do so well. Many teams have made SBCs work just fine, but, almost all of them will tell you that they keep the revs down, and make sure to have plenty of oil. Which, really, is the solution to keeping just about any engine alive in Lemons - don't rev it (cut at least 1k rpm off of the redline), keep plenty of oil circulating, and, for God's sake, keep it cool!
1996 Buick Century - we upgraded our crappy GM sedan with parts from a crappy GM minivan.
"It's got a van motor, a 220 cubic inch plant, it's got van tires, van suspension, van shocks. It's a model with the catalytic converters ripped out so
it'll run good on regular gas. What do you say, is it a racecar or what?" - Blues Brothers, Probably