just one more comment on the 302 after reading the original post...many racers like to "season" their blocks before building a race motor, use them in their tow vehicles, buy them used from a wreck, and propane motors are also a good way to go, little wear and tear but still seasoned. as far as rs, ss, models go, gm did some strange things back in the 60s, a buddy had a rs with a 6 cylinder, the rs package was considered a dress package and could be ordered with just about any combo of motors gm offered. all of the big 3 did a bit of "magic" at times, meeting requirements for production in the racing divisions, i.e., nascar required 500 units to be eligible to race in their stock class. we've all heard the stories of the nascar inspector watching and counting the cars come out one end, driven back around to the other end, dismantled and built again for the 500 quota...lol. true? i couldn't say one way or the other. i'd hate to call a man a liar on his model of car, production sheet would be nice to see though.
"When I was younger, I could remember anything, whether it had happened or not." - Mark Twain