Well heres my 2 cents worth. I have never seriously raced anything but a dragster. I just finished building my 3rd one which is a TNT supercar. We bracket race and do alot of super comp racing here in the midwest and after having both hardtails slip tube and 4 link/swing arms, there is no way I would go back to a non suspension dragster unless I was planning to go faster the 6.50 consistently. The only difference in a 4link vs a swing arm is the bottom two 4link bars are welded together with an X or something similar. The swing arm don't have to have a wishbone which is safer under heavy braking and higher HP. I am 5-10 300lbs and mine is a 24 inch cage most newer one are 23 standard width. The comment about 20 inches wide at the bellhousing is correct and this car is 21.5 wide and everything fit perfect. I love super comp racing but I believe it is the most competitive class out there for example at st louis national I'm .001 go 8.895 taking .009 at the stripe killing 4 mph my competitor is .004 8.904. Super comp is a drivers class as everybody is usually setup to go faster than 8.90 and everybody can go 00 and most are carrying .04 or .05. Most cars in super comp run in the high 160 low 170 mph range there are some 180 players and very few faster than that