There was some talk last year about using old Lear 24's and 25's for racing. There will be a lot of early Lears that won't be modified for RVSM due to cost feasibility and even after that, more stringent noise reg's are on the horizon.
The planes would be stripped of most of the avionics, pressurization etc., the tip tanks would be removed and either caps or winglets installed.
I don't think you'd have to modify the 310 airframe, if it was stripped in similar fashion. Either one would be a blast!