After I started this thread, I contacted FF for their suggestion. FF suggested the 1.06" for spirited driving and ride compromise. FF said that the 1.12" are for racing and might be too harsh on a street car.
Firm Feel deals with a fairly broad cross section of the hobby and have raced their cars in the past. I would tend to put a pretty large chunk of faith in their recommendation. I know Mitch runs the biggest bar possible and is very happy with it. As racer, his butt dyno may be calibrated slightly different than others on here who I've seen complain that .92 are too harsh. Unfortunately there is no universal measure of harshness of ride for us to compare things. We could maybe uses frequency or cycles, but that will require a bunch of research to find comparable data to dial in what cars feel like mush, feel just right, or are too harsh. That's not easy data to get.
One thing to keep in mind is that there are many competition cars running softer spring rates with higher roll rates. You want just enough spring rate to suspend the front and give reasonable dive resistance, but control transition with a lot of shock control and let the sway bar control the corner loads.
It’s a 73, right now I have 15” rims but I’m going 18’s, prob 45 series, it’s mostly street driven and I have QA1 shocks, I barely noticed any difference in going larger and a lot of guys say the same, go bigger, I also drag race and some circuit track so I’ve had to compromise some
In my experience, larger t-bars in bracket racing will not produce optimal e.t.s, but rather will produce more consistent e.t.s.
245’s up front & oversteer: Is this due to the 1.12” bars and my existing stock front sway bar?
Oversteer is too much rear rate, understeer is too much front rate. To balance the above, try a larger front sway bar.