The Grand Sport predated the other C2 Corvettes by roughly a year, with a prototype convertible being both built and raced in 1962, followed by one more convertible plus three coupes in 1963. The was as much a very serious research project as a production vehicle, and was initially secret. Eventually, 125 cars were to be built as a step up from the Z06, but this never happened after the AMA racing ban, and the subsequent cancellation of the program by GM's board of directors. In the meantime, though, the car was a promising project that many people believed (and still believe) should have been allowed to go ahead. The car was, like the Z06, very stripped-down, and meant to be barely even street legal. In actuality, the high planned production figure was for homologation purposes. No attempt was made to make the car practical off the track. The Grand Sport had disc brakes, however, and used much lighter weight materials, most notably aluminum and magnesium, resulting in a curb weight of less than a ton. The existing fiberglass body was also non-standard, as it was thinner gauge, and constructed differently, with flared fenders and additional ventilation not only for the engine, but also for the differential, which required its own cooling system. The Grand Sport also had a tube frame, as opposed to the welded, stamped steel perimeter used on the standard C2 (and for that matter, most other American cars of the period). An interesting article about the construction methods used can be found <a href="http://www.grandsportcorvette.com/ gs/gsdiff.htm">here</a>. The engine was initially the L84 327 from the Z06, at least in the prototype, but this was quickly replaced by the 377 crate engine that was then available from Chevrolet. This doesn't sound like much of a step up, but this was a full-race tuned engine with 2x 2bbl Weber side draft carbs. It was officially rated for 485 horsepower, but in the gross horsepower figures available then it put out closer to 550, and some modern, tuned examples have put out over 600 horsepower net. I've therefore been conservative with this simulation and gone for 485 net, which still makes the Redline car too fast, probably. In In any event, although GM cancelled the Grand Sport program, the cars remained in use for racing, and experienced some success. Eventually they ended up in the possession of the Penske racing team, who also bought the first ever Corvette L88 sold to the general public. Predictably, they then ordered L88 crate engines for their Grand Sports, although since that time at least one of them has been downgraded back to a 377...that dynos at 619 horsepower!!! For Redline, as I said, I've opted for the 377. Today, the real Grand Sports all still survive in private hands, and are among the most desirable of all collectible Corvettes. I figured that if I was going to do some C2 Corvettes for Redline, I had to do a Grand Sport, so here it is.