what size torsion bars should I buy?

ir3333 said
This is very subjective.I replaced my 340 .870 bars with nos .890's and the ride
was still oozy.I now have .920's with Bilstien shocks and it has a more modern feel
but you will notice rough roads.I think 1 inch would be unpleasant on our terrible roads.
..with the .920's and Bilstiens you can actually push it a bit and i think the ride is great
on decent roads.If you are blessed with lots of new pavement 1" would probably be nice.

It is a subjective subject. But I ran 1" bars on my small block Duster with bilsteins and it was still soft with tons of body roll even with crappy 225/60/15's.

I run 1.12" bars now with Helwig sway bars and Hotchkis shocks, with a small block, manual steering, no A/C, headers, aluminum intake, alumimum radiator, manual trans, etc. I drive it daily, the roads here suck, and I still wouldn't go with smaller bars. The ride is fine, very similar to newer sports/performance cars.

JoesEdge said
Running 1.03" with a small block in a '74 Duster with Bilstein shocks. It rides well, but you'll definitely notice any holes or bumps in the road especially with low profile tires. You'll hit those obstacles and you'll hear the "BANG" permeate throughout the car, but that could be because I have the front suspension set too low. It does handle better though. I'm still dialing in the suspension.

If you're getting a "bang" like that you need to find what's causing it and change it. That's not right, it's not a symptom of your torsion bars or shocks. You're probably bottoming out your suspension.