Gear Ratio to get me in the 12's?

[hookem78613]

I am looking for a little advise on how to get my car into the 12's.

It's a 68 Charger with a 500CI MP Motor running about 575 HP.  Power band is from 3000-6500 RPM
727 with 3000 stall.
Currently is has a 323 posi rear end running 295-50-15 (26.7") on the back. The tires a BFG radials.

Can anyone provide any recommendations on similar setups?  I have a friend that has 3.91 on a similar type setup and said he can't hook up with street tires at all.  He has sportsman ET's (8 lbs psi) and runs 11.95 in the quarter mile. 

Is the trick going to be the tires or in the gearing?  I think I would prefer to run a lower gear so the car runs closer to the power band. I think it would really WAKE IT UP!!  But I don't know if it's going get me where I want.  I can probably do one or the other (tires or gears) but not both.   

Hookem7813

[GoodysGotaCuda]

You have 575hp and you can't get out of 12s? You have way more issues than gear ratio, imo, even with 3.23.

Whats your 60? MPH? You should be turnin about 115mph at the end of the 1/4 if its truely 575hp at the crank.

[EVIL72]

 If you can only do one or the other, I'd say get some better tires like some sort of soft compound drag radials. Those BFG's are never going to hook up with that much motor.
 
 
 

[hookem78613]

Maybe I wasn't all that clear.  I don't know where I am at because I haven't opened it up really. Still breaking it in. I just went through the motor again and tightened it up a bit.  The advertised HP of the motor was 575 from the Mopar Performance literature...so that's what I am going by.  I have a dyno sheet with 440 at the rear wheels before I went through the motor and with a crappy dual plane intake with adapter plates.  I also had everything rebalanced and trued up plus I swamped a single plane M1 intake and put some Forged 11:1 slugs in it.

My purpose it just to get some advise on the best setup so i don't go back and do things twice.  When I started i know I wanted at least 12 second ET's so that is where I am coming from. 

[GoodysGotaCuda]

Maybe I wasn't all that clear.  I don't know where I am at because I haven't opened it up really. Still breaking it in. I just went through the motor again and tightened it up a bit.  The advertised HP of the motor was 575 from the Mopar Performance literature...so that's what I am going by.  I have a dyno sheet with 440 at the rear wheels before I went through the motor and with a crappy dual plane intake with adapter plates.  I also had everything rebalanced and trued up plus I swamped a single plane M1 intake and put some Forged 11:1 slugs in it.

My purpose it just to get some advise on the best setup so i don't go back and do things twice.  When I started i know I wanted at least 12 second ET's so that is where I am coming from. 

\

With traction, it should do 12s no problem with 3.23s imo.. You should be looking at mid 11s or so at about 114 with out much trouble with 440rwhp given the rest of the car is up to the task such as a more race orientated ratio and such.

[tactransman]

You need tires, BFGoodrich radials are terrible for traction. I recommend:
Quick Time Pro D.O.T,

[Oldschool]

You need tires, BFGoodrich radials are terrible for traction. I recommend:
Quick Time Pro D.O.T,

        BFG's won't get it done.  Several good street drag radials out there.  Hoosier's work great.  Most important---tires first, then full throttle passes/tuning too see where you are at and select the gear you want after getting the baseline information........      

Maybe a set similar to the Beast tires----"Hoosier Daddy's?"            

 

[Chryco Psycho]

my duster had 525 hp & ran 12.2 with 3.23 gears , I swapped to 4.30 gears & the 833 OD & ran 11.7 & could still street drive it