Seppo, what are you dreamin' up? It is nice to think about these things, I do it all the time.
Interesting you should ask about these classes as this is my next area of classifications with a Y-Block (2009 will be the last year for the truck). I will try to keep it short, but I need to write a little to spell it out.
Stock type coupes and sedans run in two basic categories, "classic" (1981 and earlier) and "regular" (they really don't use that word), (Usually 1982 and up) (most often Cameros, Firebirds and sometimes late model T-Birds). I don't know exactly how many years ago it split like that but it was around 2000. It gives the less aerodynamic bodies a chance to run in their own group.
In your case the EFI is not allowed in the classic category unless it is OEM. That means you would be placed in the regular classes and the records for your dream machine would be in that area.
292 cu. in. would be in the "D" class, the turbos would be considered "Blown", with no blowers available in 1960, you would have to run "Gas Coupe" instead of production. Your class would be D/BGC. The record currently is 265 and change, set in 2003.
Mechanical fuel injection or carbs would allow you to run classic and that would be D/CBGC. The current record there is 209 plus set in 1980 by our friend Gail Banks.
Our older friend Karol Miller, went just over 150 in 58 with this same kind of setup, Latham Blower (with carbs) and 259 cu. in. In 1956 he went 139 plus with a 312 E-code and in 1957 he went 150 plus with a 302 E-code (as per articles I have read).
Too much information and hard to believe? Yeah, but with new technology and deep pockets, these guys can do unbelievable things. Besides that, the current engines are almost all aftermarket parts (blocks to heads). Probably the only thing from the "factory" is a thermostat housing. By the way, this is gas, fuel adders start a "whole nother" conversation (and higher speeds).
Charlie Burns Laton, Ca (South of Fresno)
BurnsRacing981@gmail.com