the general consensus is that the extended wheelbase is best. having said that, i purposely made both my Eliminator and Street Pro car a extended wheelbase in the rear, and the standard in the front. it is harder to stabilize, but if you can pull it off it will be faster, as my new Eliminator Whiplash on its first outing had a lower ave. than my fastest single run from last year. the rears should be far back for the speed, the farther out the fronts are makes it more stable. I took a chance this year with the standard front wheelbase, I will either prove my point by getting faster as the season progresses, or have to drill new hole for the extended fronts. time will tell.
B