My 2006 mustang got to 10.0 at 136 mph with about 700 rear wheel (76mm turbo at 22 lbs boost), weighing 3850 lbs (with driver). However it had been rebuilt for dragracing, launching off a transbrake and 2 step, with full slicks and skinnies and spooled.
At last years TX2k10 event, Keith (Viperless, GenIV) ran a 10.76 at 133 using only drag radials (with 1.7 60ft I think) and a mere 585whp. Add some slicks and a good drag suspension and I am certain 10.4s or even 10.3 can be had with that power.
Once you get into the 10 second area there are many drag rcing rule changes. Not sure I want to go there without some serious mods. I probably will never see 10 in my car but, still fun to blast down the 1/4 mile. 11.5 is my best.
The stang is headed for low 9s. At 135+ traps, need a cage. The interior of the stang, that I bought new in 06, had been gutted along with the rest of the car. My viper is not going anywhere near a dragstrip or dyno machine for that matter...lol. It's just fine 100% stock.
Really depends on the powerband more than just the just the RWHP number. My 06 Viper Coupe with a Paxton had 700rwhp and only trapped like 129-130mph. Even if I would have bumped it up another 100rwhp on that setup I don't think it would have went much faster than 10.5's. The paxton was great for making a big number on the dyno, but wasn't very impressive at the track.
Now if it was twin turbo'd or a Roots style blower with the same HP number's, I think 725 would probably be more than sufficent.
I went 11.3 @125 in my Gen II in around 70 degree temps. That was at about 455HP / 460TQ. Drag Radial, NO burnout, only spun the tires to get the dirt off. Slicks & Skinnies and a line lock for a good hot burnout and it will do 10's I'm sure of it. Heck, I feel pretty good about getting even closer to a 10 sec pass on the Drag Radials if it were cooler out or had I done a proper burnout. Add 200HP to that from a Paxton and I bet it would go deep 10's...
There are alot of factors to hitting those times. I know with my car, I couldn't even get it into the low 10's but my mph was almost 170. My 60' times were around 2.0-2.2. Once I got the launch down my 60's went down to 1.3 then my times went to 9.3 without really pushing the car very hard.