I have a stock geared 727 in my cuda and I use 295 drag radials. Motor makes somewhere around 850 hp, plus 300 hp of nitrous.
With a 4.10 rear gear, the SLR was 10.0 and it was uncontrollable on nitrous. I rarely ever got it to hook, but when it did, it just did wheelstands. I had a couple of "good" passes where it went fast, but the vast majority of runs were aborted.
I swapped in a 3.54 gear for an 8.67 SLR and it made a HUGE difference. It has hooked almost every pass since. The only time it didn't hook, I had the front shocks set too loose.

The drop in SLR hasn't seemed to affect the ET much so far...on the nitrous anyway. I'm still tuning this thing, so getting it to hook and repeat has been priority.
With the tight 4k nitrous converter and 3.54s it still ran 9.69 at almost 142 mph on motor only, super sluggish 1.43 sixty foot.
Best NA pass w/ loose 5k converter and 4.10s was 9.54 at 140.4 mph, 1.32 sixty foot. The car would usually hook anywhere the track was at least halfway decent w/ the NA setup.
At my car's weight (over 3800 lbs), I really need a different trans.