Race/ slant 6 torsion bars

I have a thread on the suspension section but i feel this question will get a better group to answer.
First off it a E body not A
The only "race" torsion bar i can find is from "Firm Feel" and it is a .845" bars.
clean my bar and put a caliper on it. the close as i can tell its a .884"

Have found .810s for a A body but Not a E

Is .039" smaller diameter going to be that big of a difference for stored energy for a drag car?
and is it worth the 400 dollar price tag.

Put a want add in the E body form, but have got 0 response for a Slant 6 bars

Anyone know of a place that sells them......and hopefully for a lot less money.....