Wheels And TiresProbably the single biggest improvement you can make to any vehicle's appearance is to change the wheels and tires. Altering the type, size, and style of the rolling stock has been popular since guys first started messing around with cars and will likely continue until The Jetsons era arrives. If your car is from the late-'50s through early '70s, it probably came with narrow 14-inch rims and tiny bias-ply tires. Aftermarket wheel swaps were popular by the mid-'60s, so if yours is a performance model, it may have received a set of American Racing Torq-Thrusts (or a clone from another manufacturer), Cragar SS wheels, or something similar. Wheels like these are back in vogue, so they're good to have. Unfortunately, it's more likely that any cool wheels installed in the '60s were swapped in the '70s or '80s with something less desirable.
Although the Cragar SS remained popular through the '80s, Torq-Thrusts and the like were not only out of style, but out of production. In their place came a wide variety of chromed "tech" wheels that today are truly hideous. Some of these were even offered in gold tone, or perhaps worse-faux anodized colors.
These evils can be cured in no time flat by installing something less trashy. A factory rally wheel might be the simplest solution, or maybe even a set of plain-steel wheels with poverty caps. If you go this route, try to move up to 15-inch rims that are at least 7 inches wide so you can dress them with suitably meaty rubber.
Of course, you could step up and try the larger-diameter wheels and tires that are all the rage these days. Although some may scoff at the whole Pro Touring thing, we find that big-inch rollers, if selected properly, can really make cars look tough-especially big, old cars with huge wheelwells. You can try some of the big-inch rally wheels offered by Wheel Vintiques, Stockton Wheel, and others, or choose a larger-diameter version of a traditional wheel; both Torq-Thrusts and Cragar SSs can be had all the way up to 20 inches.
DrivetrainWhether you opt to upgrade to a late-model engine or not, you may still want to consider giving your existing powerplant a drivetrain makeover. Currently, the most popular trend for vintage rides is a swap to an overdrive transmission. This includes automatics or manuals, and in many cases, isn't too tough. Chevy fans have the venerable 700-R4, which is pretty much a bolt-in deal, though driveshaft mods will usually be required. There's also the 200-4R, which maintains the same overall dimensions as the super-common Turbo 350 and Powerglide and can also be fitted to Buick/Olds/Pontiac bellhousings. Ford guys have the AOD, but that will only mate to small-block bellhousings. Even Mopars can be fitted with automatic overdrives by using the A500 or A518, which are overdrive versions of the old TorqueFlite 904 and 727 'boxes, though again, adapters are required for big-blocks.
For manual boxes, the choices are more diverse. Ford and GM products were fitted with overdrive five-speeds at the factory, usually incorporating a Borg-Warner T5 gearbox. Though that trans isn't known for its durability in severe duty, the Tremec five-speed is, and it's offered in swap kits for Ford, GM, and Mopar. Richmond Gear offers a five-speed box that easily replaces many four-speeds (though Fifth gear is 1:1) and also offers an overdrive six-speed. Overdrive six-speeds have also been offered by some OE manufacturers for nearly 10 years now, mostly from GM.
But maybe all you really need is a rearend swap. Those 4.56:1 gears may have seemed cool back in the day, but now they're just aggravating. Swapping to a set of 3.42s or even 3.08s might suit your needs better, and you'd be amazed at the difference in road manners on the highway.