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#1 |
Registered User
Join Date: May 2012
Location: Pennsylvania
Posts: 132
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gearing and ratios
1985 chevy, 350 crate motor, carbed, 700r4 trans, 35 inch tires, axle gears 3.08s, transfer case is np 208, good or bad idea?
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#2 |
Newbee
Join Date: Jan 2010
Location: Phoenix, Arizona
Posts: 1,406
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Re: gearing and ratios
Probably want to go 3.73 with the OD.
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#3 |
Senior Member
![]() Join Date: Mar 2003
Location: Colfax-California
Posts: 8,528
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Re: gearing and ratios
35'' tires and a 700................4.56 gears
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#4 |
Fabricate till you "puke"
Join Date: Jun 2002
Location: Ill
Posts: 9,403
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Re: gearing and ratios
35" tire, I would also go 4.56 on the gear
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69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears.... |
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#5 |
60-66 Nut
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Location: Coeur d'Alene, Idaho
Posts: 23,247
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Re: gearing and ratios
I agree with a 4.56 gear with those 35" tires. The 3.08 gears with 35" tires would just be absurd.
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#6 |
Registered User
Join Date: May 2012
Location: Pennsylvania
Posts: 132
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Re: gearing and ratios
Alright sounds pretty conclusive, 4.56s it is. Haha and just curious if i switch the gears, how would it run with 33s? Mpg? performance? over all? Cause most likely it'd be a lil while b4 35s.
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#7 |
Registered User
Join Date: Oct 2009
Location: Great White North
Posts: 1,520
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Re: gearing and ratios
Check out this website. Great driveline / gear / tire calculator. Use the drop downs to input your tranny and transfer, then input your tires and change up the gearing till you get the rpms where you want them at specific speeds. Can also do a side by side comparison.
http://www.grimmjeeper.com/gears.html
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#8 | |
Fabricate till you "puke"
Join Date: Jun 2002
Location: Ill
Posts: 9,403
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Re: gearing and ratios
Quote:
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69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears.... |
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#9 |
Registered User
Join Date: May 2012
Location: Pennsylvania
Posts: 132
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Re: gearing and ratios
Which sounds good, but if I'm going over to the 35s sometime this winter there's no use putting gears that match up with 33s, see what I'm saying? Might as wel gear for 35s, an run 33s for a while
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#10 |
Senior Member
![]() Join Date: Mar 2003
Location: Colfax-California
Posts: 8,528
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Re: gearing and ratios
Even 33s with a 4.56 will be fine. I had a 1990 suburban years ago that I had put in 4.56 gearing with 31'' tires, and the 700 ... best change I ever made. You got to remember when the trans shifts into 4th and locks up the convertor you are reducing the effective ratio by almost a third. So your 4.56 becomes just around a 3.2 ratio final drive. Stick with the 4.56
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#11 |
Registered User
Join Date: Oct 2009
Location: .
Posts: 2,185
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Re: gearing and ratios
I had 3.08 and 35 on my 85, I don't think it ever shifted into overdrive until 60+
Another option would be a 3/4 ton rear or swap to 1 tone axles, if you still have 2 10 bolts. |
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#12 | |
Fabricate till you "puke"
Join Date: Jun 2002
Location: Ill
Posts: 9,403
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Re: gearing and ratios
Quote:
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69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears.... |
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350, 35s, 700r4, gearing, ratios |
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