71 duster 416 12-1 360-1 indys ported 272@50 590 lift 108 cl 105 icl installed 904 8inch 5500 coan 2.75 first gear. the car has 3.54 gears in it I was thinking of tryin this with a 26 11.50 tire. Car has caltracs on it. Or is it a waste of time and just put the 4.10 back in it with a 28 inch tire. or leave the 3.54 28 tire and spray it with 125n2o.

Have you run it as is?

Always run what you have first.

Ditto

I would try what I had in it first See what RPM it crosses the finsh line with the NOS and without and then decide I'm assuming you have both gears sets ready to go that is I have tested a bunch of different gear ratios in Mopar cars over the years, both BB and SB, all N/A though, most of them didn't gain or loose a bunch in the 1/4 mile, that was going from 3:55 to 4:89 in a SB 4 speed car with a pump gas 366 C.I. mild motor, I did try 3:73, 3:91, 4:10 and finally 4:30 in my old pump gas Duster 518 C.I. low deck six pak stroker motor. That stupid dang car didn't change much at all with all those gear ratio swaps It did spend more time in high gear with the steeper 3:91, 4:10 and 4:30 gears but not much ET or MPH gain
With the low gear set in it will go into high gear sooner than it would with the stock low gear
I did that swap in my old NHRA stocker, removed the 4:89 rear gears and put in the 2:77 low gear set and 4:56 in the rear, that helped the 60 ft and reaction times
IHTHs

About 3 years ago I broke my 5.14 gears and threw in a set of 3.50's and I slowed down from a best of 6.34 @ 108 to a 6.39 @ 109 crossing the finish line in second gear. I was running 1/8 mile. I am running 4.56 now. It is a 394 ci small block.

great thanx guys 3.54 first

How often do you plan on spraying it.. granted your only
talking a 125 shot.. but your are playing in 2 worlds..
if you spray it the rpms will be up... try what you have
then decide on a gear.. you can do it with math but with
out the spray