There are quite a few mods allowable under the current SCCA rules for Street Prepared, section 14 covers them. The listing for the Corvair in the appendix includes all years of Corvairs, and stages I, II, and III of Yenko Stingers. When I discuss Corvairs in the text, it includes the Stingers.
- 14.1.C: Allows updating/backdating. This means you can *bolt* any part from any other 'Vair onto your car, however this does not include modifying the car to accept the part. Therefore, swapping an engine from a late to an early is legal, but swapping in the late model rear suspension is not. Speaking of engine swaps, the engine, trans, and diff must be swapped as a unit, i.e., you may not put a 102 cam in a 140. You may, however, run a "304" factory turbo cam, since that was the last service part available.
- 14.2.A: Fenders may be modified for tire clearance. This includes rolling the fender lips, but be careful if you trim off the entire lip, as the fenders on a Corvair are part of the structure. Since a full roll cage is not legal, you will need to tie the fenders and fenderwells back together for strength.
- 14.2.C: Strut bars are legal, but they can only run straight across. This may not be an obvious mod for a Corvair, but it should be possible to stiffen the car with a bar tying the frame rails together at the suspension mounting points.
- 14.2.D: Any seat is legal.
- 14.2.E: Any steering wheel is legal. See Seth Emerson's articles in the Corsa Tech Guide about wheel swapping.
- 14.2.F: Spoilers, but not skirts, are legal. See the rule text for specifics on size.
- 14.3: Tires. Basically, any DOT legal tire is allowed, which includes the various "R" series tires.
- 14.4: Wheels. Anything you can bolt on :-) Flaring and cutting for clearance is legal.
- 14.6: Brakes. Dual master cylinder conversions, boosters, and proportioning valves are free, but not disk brake conversions. Since drums are lighter anyway, this isn't really a problem.
- 14.7: Sway bars are free.
- 14.8.A: Ride height is free, but can only be changed by cutting the springs, adding spacers, or modifying the perches. The springs themselves are free, but must be of the same type (sorry, no coil-overs). On '64's, the leaf spring is also free, and you can update an earlier 'Vair with one if you wish.
- 14.8.C: Bushings are free, but cannot be changed to metal or spherical joints.
- 14.9.A: Ignition is free.
- 14.9.B & 14.9.C: The battery is free and it can be relocated to the trunk, but must still be 12 volts.
- 14.9.D: Any bolt in starter and generator/alternator is allowed, as long as the alternator has an output greater than or equal to stock (30A for earlies, 37A for lates). It might be possible to adapt a new, lighter starter to the Corvair starter nose.
- 14.10.A: Oil pumps, pans, pickups, coolers, and filters are free. An accusump may be added, but dry sumps are not allowed.
- 14.10.C: Carburators and FI systems which can be bolted on are free. Turbos may *not* be modified in any way (sorry).
- 14.10.D: The air cleaner housing is free.
- 14.10.E: Emission controls are free.
- 14.10.F: Water injection is legal.
- 14.10.G: Fuel lines and pumps are free. Cool cans are *not* legal.
- 14.10.H: The exhaust is free,as long as it is quiet. One reason to make the effort to seal those headers.
- 14.10.I: A bolt on torque supressor is legal. A nice way to do this would be to run a rod from the lifting eye on the bellhousing to the driver's side frame rail.
- 14.10.J: Fan and shroud are free, including electric fans.
- 14.10.L: Clutch, flywheels, and torque convertors are free.
- 14.10.M: Any mechanical shifter is legal.
- 14.10.N: Limited slips diffs are legal.
- 14.10.P: Balancing the engine is legal.