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Author Topic:   Which gearing
Bill Adkins
unregistered
posted July 06, 2001 01:46 PM           
I have a '70 chevelle that I will race on 1/4 mile dirt, 350 motor w/ rv cam, turbo 350 trans, turning 5-5500 rpm's. Which rear end gears should I run?


VIPER000
Member
posted July 06, 2001 01:50 PM
you will need to ask the local guys but i would say somewere around 6.0. with only turning 5500 and assuming you have a quality engine i would bump your existing ratio about 10% to put you at around 6000

[This message has been edited by VIPER000 (edited July 06, 2001).]

Bill Adkins
unregistered
posted July 06, 2001 04:38 PM           
quote:
Originally posted by VIPER000:
you will need to ask the local guys but i would say somewere around 6.0. with only turning 5500 and assuming you have a quality engine i would bump your existing ratio about 10% to put you at around 6000


[This message has been edited by VIPER000 (edited July 06, 2001).]


[This message has been edited by Bill Adkins (edited July 06, 2001).]

Bill Adkins
unregistered
posted July 06, 2001 04:41 PM           
I asked a guy at our local racing shop he told me 2.73's is where i should start.
quote:
Originally posted by Bill Adkins:

[This message has been edited by Bill Adkins (edited July 06, 2001).]




racer17j
Member
posted July 06, 2001 10:11 PM
what tire roll are you running and what gear do you plan on running the trans in?


Racer4
unregistered
posted July 06, 2001 10:20 PM           
I assume you are not running a nine inch and will not be in final gear. Depending on the lift of your cam i would try to be at least 6.2 to 6.5 on your final gear. Like a truck powerglide in first with a 3.42 rear. Make sure your car is setup, and get some good tires and shocks.


racer17j
Member
posted July 07, 2001 12:00 AM
yuo could get the 6.2 final in 2nd gear on your t350 with a 4.10 rear thats about the ball park that i would run on a 1/4 with about an 84 in roll tire

[This message has been edited by racer17j (edited July 07, 2001).]

Bill Adkins
unregistered
posted July 07, 2001 02:57 PM           
quote:
Originally posted by Bill Adkins:
I have a '70 chevelle that I will race on 1/4 mile dirt, 350 motor w/ rv cam, turbo 350 trans, turning 5-5500 rpm's. Which rear end gears should I run? The rear end is a chev. 12 bolt and running 15 X 7 " wheels



Bill Adkins
unregistered
posted July 07, 2001 03:02 PM           
Some guy's said to run in 1st. but it sounds like I can get the gearing I need in 2nd. One place I called about gears said they don't make 2.73's for 12 bolts. Let me know what you guy's think Thanks
quote:
Originally posted by Bill Adkins:



racer17j
Member
posted July 07, 2001 05:00 PM
are you required to run a spec size tires? you would need to gear it differently if you have to run 205 compared to say 235 or bigger take a tape and messure the roll of the tires you plan to run to get a better idea what your final gear should be as for the gear you have to work with they make 3.08-6.14 for a 12 bolt

[This message has been edited by racer17j (edited July 07, 2001).]

Bill Adkins
unregistered
posted July 08, 2001 09:48 AM           
quote:
Originally posted by racer17j:
are you required to run a spec size tires? you would need to gear it differently if you have to run 205 compared to say 235 or bigger take a tape and messure the roll of the tires you plan to run to get a better idea what your final gear should be as for the gear you have to work with they make 3.08-6.14 for a 12 bolt Thanks racer17j the tire size is a 215's. I went to the race's last night to ask around and some guy's said run 3.08's with the t350 in low 1st would do the trick. 1st in the t350 is 2.72? right. So that would give me what I need.

[This message has been edited by racer17j (edited July 07, 2001).]




racer17j
Member
posted July 08, 2001 12:23 PM
we have ran 308 in 2nd on 1/4's but we were running liny tires i think a 75 in roll i assume your tires will comeout somewhere around 85-88 if you run it in 1st that would put you at about a 7.76 if you want to only pull 5800 you are gonna have to pull about a 6.20-6.5 so i still think your best bet would be a 4.10 in 2nd gear thats what i would do anyway


Bill Adkins
unregistered
posted July 08, 2001 08:09 PM           
quote:
Originally posted by racer17j:
we have ran 308 in 2nd on 1/4's but we were running liny tires i think a 75 in roll i assume your tires will comeout somewhere around 85-88 if you run it in 1st that would put you at about a 7.76 if you want to only pull 5800 you are gonna have to pull about a 6.20-6.5 so i still think your best bet would be a 4.10 in 2nd gear thats what i would do anyway I thought a t350 in 1st was 2.72 and 2nd was 1.52 would it not be best to have a 2.73 in 1st. That would give me 7.42 or 6.23 in 2nd. what do you think Thanks Bill



racer17j
Member
posted July 09, 2001 01:14 AM
ya that would work in 2nd if you could find that gear for your rear but i have never seen anything lower than a 3.08 in any of my mags maybe out of a stock something if you were to run it in 1st you would be a rocket off the corner but you'l turn way over what you are aiming for by the middle of the straight


Bill Adkins
unregistered
posted July 09, 2001 10:21 AM           
Thanks racer17j for the help. I will start with what you said and go from there.


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