BFG DR Questions

Currently, I have 275 / 40 / 17 BFG DRs on my 2k3 5-speed GT. I've got 4.10s. As compared to my stock tires, my 1/4 mile trap speeds dropped about 4-5 mph on average. My 60 foot times dropped from 2.3 to 1.9 so the car hooks really well now.

1. What kind of a drop in ET could I expect by switching to a 295 / 50 / 15 BFG DR? Would the diameter of this tire be in my favor for getting down the track more quickly?

2. If so, then where does one find a 15 x 9.5 inch wheel to accommodate these tires? A cheap steel wheel would be fine.

Thanks for the advice.

My best E.T. with the stock tires was a 14.38. Had a number of 2.3 second 60' times. Best E.T. thus far with the drag radials is 14.31, but I now have 1.9 second 60' times. I've been running 14 psi in the DRs and am launching at 3500 at the line. This results in a solid hook with no tire spin. I powershift at red line -- have tried other RPMs, but this is most effective.

Other than the gears, the only performance mod mine has is the plasma booster. I put my money into my suspension (Hotchkis TVS) and shifter (Tri-Ax) first so that I would be able to realize the benefits of any hp add ons. Other similarly equipped 'stangs are running 14.60s plus at Firebird.

I hope this helps.