@dlearl476 posted:IIRC from the article in Kit Car that originally piqued my interest, back in 89 or something, I seem to remember it said Chuck lengthened the Spyder 2" and widened it 1" or vice versa, to make it easier to get in and out.
Beck Spyders are just about four inches longer than an original 550—146 inches against 142. Some of it is in the tub for leg room. Some is ahead of the front firewall/bulkhead to allow for the use of a dual circuit master cylinder, some is behind in order to keep the proportions looking right. The Beck wheelbase is 84.7 inches, comparted to the original car's 83 inches. I am not certain that the car is also wider, but I believe it is, as mine measured 61.5 inches and the original cars are supposed to be 61 even. The height is slightly lower than the originals, though that may be a product of the lower profile tires and smaller wheels on most replicas.