Theres a video on Youtube of Opp and Ziggy from 1974 Eldora USAC and Ziggy has down tubes.

I also seen Champ Cars with em way before 86. I believe some of these were Bolt on.

IMHO there was never any proof that Down tubes made cars faster, Wolfie, Shnee, Swindell Challenger, Allen continued to run with and win for at least ten years after Down Tubes became commonplace. I think Stealth even had Non Down tube cars up till around 2005.

From a safety standpoint, I'd never argue against the down tubes.


https://www.youtube.com/watch?v=MuEf6sbvLPc