old NASCARS, etc - why the lowered bodies on short-track cars?

[Mike DC]

                                           
The main reasons for lowering a sports car are no secret.  Lower center of gravity to reduce body roll.  The lowered roll centers would be a positive in some cases although probably not all cases.  



But what about GN type cars, where they "lowered" the car mostly by mounting the roof/sides down lower on the chassis?  The car's CG height would not change significantly and the roll centers wouldn't move at all.  

The smaller hole in the wind makes perfect sense.  I'm sure that would have been the overwhelming reason to do it on a GN car destined for the big tracks.  But I don't see the reason for this on short-track cars and amateur dirt ovals where aero makes little or no difference.  But a visibly lowered body seems to be a pretty constant thing for ANY old musclecar racer from that era.  

[RTDaddy]

Most of the cars built then were quite a bit lighter than the existing rules.  The typical way to get the car up to weight was lead in the frame rails along the rockers, so the lower the car, the lower the weight in the car.  Add to this that a lot of the "short track cars" back in the day were the previous year's speedway car, which as you say was built lower to make a smaller hole in the air, so things kind of trickled down.

"IF YOU'RE UNDER CONTROL, YOU AIN'T GOING FAST ENOUGH."   

[Mike DC]

                   
Would the framerails & lead ballast really be lower in height because of a lowered body, though?  I thought the lowering methods left the floor/framework as part of the less lowered portion, and they brought down the sides & upper part of the body. 

The carryover habits from speedway cars to dirt tracks was another thing I was suspecting.  Either direct carryovers or just habitual building methods for both types of chassis.