Here's a little story about adjusting wheelbase- - - - - -when I ran the crew on a dirt track car in California, the minimum wheelbase for the class we ran (Northern California Sportsman) was 106". We ran a piece of channel iron as a spring mount with several holes in it, and partway through the season we would move the rear axle forward a bit. With open wheels and rub bars between the front and rear wheels there was no fender opening to be concerned with, and by the end of the season just about everybody at the track was running a wheelbase close to 102"! I had a couple of shorter driveshafts made up, as shortening the wheelbase for better cornering would make the slip yoke bottom out in the transmission. A shorter wheelbase made for much better handling in the turns.
Jerry