Help me pick a gear

[SRT440DUSTER]

I am currently running a 440 with 509 cam, hughes 300 stall convertor. 727 auto, Im trying to figure out what would be the best gear ratio to go with..i Plan on putting a bigger cam in it down the line, but nothing that radical..probably nothing more then the 590 cam...although ive been planning to put the .545 comp cam because the recommended cylinder pressure is in my ballpark. Its a cast crank motor so i dont plan to spin the motor much more then 6300 through the traps...suggestions?
thanks
Jeff

[sunsetdart]

Alot depends on rear tire height. There is a formula that will give you what exact ratio you will have after putting in whatever gear you want.........example: I have 4:11's in mine, I have 33" tall tires, so with the formula ,I figured out my "true ratio" turned out to be 3:92 , which is fine for street and some fun racing. If you're going to go serious racing, you may need to go to 4:56 or 4:88 and then see what tire height is.

[abodyjoe]

with a 509 cam its gotta be atleast  3:91. after that it depends on yout tire size.

[cory]

 
unless u want to fly

[austinbbmopar]

unless u want to fly

Sounds tempting how bout some 2.94s and 33in tires.... will that get you airborne?  Im running that cam in a 383 a 4000 stall and 391s with 275 60 15s.

[Womanator]

Magic number with a 509 would be 3.91's

[75Dart440]

Sounds tempting how bout some 2.94s and 33in tires.... will that get you airborne?  Im running that cam in a 383 a 4000 stall and 391s with 275 60 15s.

Currently, I am building a 3.91 sure-grip center, so still using the stock 2.94 open unit in the Dart with a 3400-3800 stall converter and .513/537 Lunati cam.  Man......will that right tire spin fast and make some smoke!! 

[PureGTS]

In your case I'd go 4.30's with a tall tire 275/60 or 325/50's, get as much width as you can. Traction IS everything (scare tactics are secondary).

I've run the .509 with 3.23, 3.55, 4.30, 4.88 gears
.509
3.23 w/ 275/60R15 - good for all around use (got better mileage than my wife's Wrangler)  No data taken
3.55 w/ 29.5x15.5 M/T street tires - same (but looked really cool when lowered 3 1/2") No data taken
4.30 w/ 10.0x30.5x15 slicks - strip only - topped out around 6200RPM at the far end; been a while though (1993)
4.88 w/ 11x28x15 Hoosiers wrinkle wall strip only - holding at 7000RPM through the traps (I remember this one distintly!)
4.88 w/ 10.0x30.5x15 slicks - strip only - Broke axle - no data taken - end of trip

The .590 got:

4.57 w/ 10.0x30.5x15 slicks - strip only - topped at about 6400 at the traps (6500 rpm shift point)
4.57 w/ 11.0x28x15 slicks - strip only - tops at 7000 RPM at the traps (same shift point; better ET's)

[SRT440DUSTER]

wow...great answers guys!...are you guys fitting these tires in a stock wheel well with inboard springs?

[383man]

What is the car used for ?  Is it a street/strip car ?  For an idea my 63 and my boys Dart are street/strip cars and since he has a small wheelwell on the Dart he stuck with 3.91's and a 26" tall tire.  But he really wants more gear as he winds the 400 up to 6800 and it likes it.  But in my 63 I fit a 29" tire in the stock wheelwell so I use 4.30's and I love them.  I drive the car to the track and all over as at 60 mph it turns about 3200 rpm which is nothing to me.  I love driving it all over and I love the launch the 4.30's give me.       Ron

[SRT440DUSTER]

Its more of a limp around on the street drag car.

[PureGTS]

My numbers are from a B-body. But the engine, trans, gears and tires can't tell the difference between an A or a B, much less a C, or otherwise.