Gear ratio/ Tire size

stocker396 · 04-22-2022, 10:41 PM

Trying to see what the general consensus is on recommended gear ratio would be in conjunction with tire size.
396 / 325 Automatic 3 speed 2.75 low 4:88 or 4:56?
92.5 “ or 94” Hoosier radial?
Would it be the same for 360/340hp (bigger cam) as well?
Wanting to hear about real world tests/results?
Help appreciated. Thanks in advance.

GTX JOHN · 04-23-2022, 12:04 AM

4.56 and either tire size would be my suggestion.

I think the 325 / 396 is not a super high rev combo.

TommyPettigrew3076 · 04-23-2022, 10:28 PM

Find a chassis dyne throw it on there see where the motor is actually make power and torque . Unless you your combo is built identical to others running the same stuff you are just guessing where it wants to be . I would think someone would chime in that runs that combo I know there are a lot of them out there

ken robinson · 04-26-2022, 11:40 AM

There's only 100-150 RPM difference between the 92.5 & the 94 .

Chipper Chapman · 04-26-2022, 06:01 PM

Mine likes 4.33 in F weight, 4.56 in G weight. They don’t have a ton of RPM on tap. With the 350hp combo 4.56 would likely be okay in the lighter class, but the cam doesnt seem to increase RPM range by much.

04-22-2022, 10:41 PM	#1
stocker396 Member Join Date: Dec 2013 Location: Santa Fe TEXAS Posts: 109 Likes: 2 Liked 58 Times in 16 Posts	Gear ratio/ Tire size Trying to see what the general consensus is on recommended gear ratio would be in conjunction with tire size. 396 / 325 Automatic 3 speed 2.75 low 4:88 or 4:56? 92.5 “ or 94” Hoosier radial? Would it be the same for 360/340hp (bigger cam) as well? Wanting to hear about real world tests/results? Help appreciated. Thanks in advance. __________________ Overkill is Under-rated

04-23-2022, 12:04 AM	#2
GTX JOHN VIP Member Join Date: Jun 2009 Location: Boulder City, Nevada 89005 Posts: 2,708 Likes: 2,732 Liked 2,398 Times in 679 Posts	Re: Gear ratio/ Tire size 4.56 and either tire size would be my suggestion. I think the 325 / 396 is not a super high rev combo. __________________ John Irving 741 Stock 741 Super Stock

04-23-2022, 10:28 PM	#3
TommyPettigrew3076 Junior Member Join Date: Sep 2006 Location: Fishers Indiana Posts: 58 Likes: 9 Liked 23 Times in 9 Posts	Re: Gear ratio/ Tire size Find a chassis dyne throw it on there see where the motor is actually make power and torque . Unless you your combo is built identical to others running the same stuff you are just guessing where it wants to be . I would think someone would chime in that runs that combo I know there are a lot of them out there

04-26-2022, 11:40 AM	#4
ken robinson Member Join Date: Dec 2001 Location: tomsriver nj Posts: 470 Likes: 70 Liked 203 Times in 82 Posts	Re: Gear ratio/ Tire size There's only 100-150 RPM difference between the 92.5 & the 94 .

04-26-2022, 06:01 PM	#5
Chipper Chapman Member Join Date: Jan 2004 Location: Belmont N.S. Canada Posts: 473 Likes: 246 Liked 163 Times in 71 Posts	Re: Gear ratio/ Tire size Mine likes 4.33 in F weight, 4.56 in G weight. They don’t have a ton of RPM on tap. With the 350hp combo 4.56 would likely be okay in the lighter class, but the cam doesnt seem to increase RPM range by much. __________________ Chris Chapman 1969 Chevelle NHRA F-G/SA 1090