A local track R32 is down to 1190kg, that's with an extensive cage. It's stripped as light as you can go with Targa regs, but it's still got a gtst bonnet. So 1176 with gtr bonnet?
I'd guess 1280 would be about it on a R33, with it's gearbox, and extra body bracing. If we could run carbon doors it'd make a huge difference.
Woosters R32 was about 1240kg, and i'm aiming for under 1200kg with mine. Alot easier to do with a flimsy R32 and little gearbox.
a 12l dry sump would be heavier than a wet sump.