4.10 or 4.30?

I'm about two steps away from having the car finished (for now - you know how it is), and one of those steps is a gear swap in my 8 3/4.

Right now, I'm running 3.23 Sure Grip in a 489 case (freshly rebuilt, green bearings, axles, etc.) - which I know are completely the wrong gears for my setup.

I've got a 413 that is putting out about 450 - 475 to the crank. Power is going thru a built 727 Torqueflite with a 9.5 inch California Converter by Art Carr TC. Stall is around 3,800 RPM.

You can see that makes for an interesting combination with the 3.23s! It just won't lock up (which goes without saying). Fortunately, the thing has never heated up or been flogged.

I need the gears to make the combo - so my thought is going with either a 4.10 or 4.30 ratio. Car is for the street. Very little highway driving. Occasional blast down the 1/8 mile.

Any thoughts on the gears to get here guys and gals?

Tire size will be your deciding factor.

Anything less than 30", and i think the 4.30's are a bit steep.

FWIW, I had 4.30's in my car, and switched them down to 410's. Liked them, but made highway time a little crappy.
Since then, I've gone one more step down to 3.73's

I would think you are better to narrow the choices to 410's or 391's, but that's my .

how tall are your tires?

4.30's are a lot of gear with less then 30" tall tires on the street

Back when I used to drive around on 4.10's with a 28" tall tire not too bad.

Keep in mind that there is approximately a 5% difference between 4.10 and 4.30 gears. For examle: If you would cruise at 3000 rpm with the 4.10's, with the 4.30's you would go the same speed at 3150 rpm. Big woop. You'll barely notice the difference. For the usage you described I would probably get the 4.30's and use a 28" tire.

I run 4.30s with a 275-60-15. 70MPH is not bad. It's a little noisy, but hot rods are supposed to be noisy.

this one is easy....
you said no highway driving and 1/8 strip use to me = 4.30

With the weight go with the 4.30s no difference in gas mileage period between the 4.10s and 4.30s. I love the 4.30s in the 1/8 mile

I'm running 275 60 15 on the back, so that's a 28" diameter tire, I believe.

What is the rpm range of your cam and where do you shift?You won't likely run out of rpm in the 1/8 but I would'nt want to be done at 100 mph either.
Another thing I would consider is how well your car will hook.If it doesent hook the more gear you throw at it the more et it will lose.

I believe the RPM range on the cam is 1,500 to 7,500 if I'm not mistaken.

1500-7500 usable rpm?
i think not. more then likely if its a true 7500rpm camshaft,
there will be nothing under 3000rpm.

Like I said, I could be wrong!

I got home and dug out my cam specs (it has been a few years since I looked). Here you go:

Melling Performance 440 (#23302 WG-1031)
Cam Lift (int/exh) .320/.320
Valve Lift (int/exh) .480/.480
SAE Duration (int/exh) 302/302
SAE Timing: BTC = 43; ABC = 79;BBC = 79; ATC = 43
Lobe Center (int/exh) 108/108
Lash Hot (int/exh) HYD/HYD
.050 Duration (int/exh) 236/236
.050 Timing BTC = 10; ABC = 46; BBC = 46; ATC = 10

melling eh? anyways.. 4.10 or 4.30's won't make a difference IMO.

Thanks for the advice.

I would say 4:10's
that isnt that much cam.
I have 3:54's in mine and it's not bad. I have alot more cam than you do but I have a 4spd and that seems to help. I am going to 4:10's this winter though.

With that cam in a big block I'd find a used set of 3.91s, my 440 loved them with pretty much the same cam. That being said I changed my 3.91s to 4.30s in my street/strip small block Dart and only picked up a few hundreths in the 1/8. On the street I could tell a difference, most likely the 3.91s will go back in. I too run a 275/60. It ran 11.62 @ 115 in the 1/4 crossing the stripe at 6500 rpms with the 4.30 gears.