[masraum]

To be a more direct response to the OP.

Good luck. I'd say that it's kind of the luck of the draw, but if you want to maximize the chance of increased value (there's no guaranty that he'll be able to make money in 2-3 years, much less make a ton of money) then I would stick with numbers matching, special hi-perf engines and options. IE, if it's a camaro, RS, SS or RS/SS, 396, 427, 302 COPO type options, mustangs would be top performance motors, mach 1, Shelby, etc..., 'vettes would be the high perf big blocks or maybe an LT1 with other desirable options. Other cars to look at might by Chevelles, GTOs, 440 or 426 Dodge/Chrysler stuff.

Numbers matching would I think be a pretty big deal in the collector car arena, so that everything is original as the car came, not a home made LS6 454 or a home made Shelby mustang.

If possible, then super clean and unrestored, but a car that has been perfectly(documented) restored would be an option too.