Rear gear

Dave_mustang_50 · 06-11-2005, 09:57 AM

Ok, Im planning on ordering a rear gear for the Mach. The thing is, i`m not sure which gear it has without pulling it out. The car has a c6 and it shifts into 2nd at 50mph wot and into D around 90mph. The highest gear i have seen is a 3.50, but the car came with a 3.00 according to the warranty plate. Right now im thinking of either the 3.70 or the 3.89. This isnt a highway car, but i`d like to be able to cruise 80. anyone have any experience with the c6 and these gears with a 351?

Phillyfanfrombirth · 06-11-2005, 08:01 PM

Is there a tag on the front of the pumpkin?

The tranny won't matter much since it doesn't have an overdrive... everything will be 1:1. 3.89s are a little steep for street use, for better driability I'd say 3.50s would be a good choice unless you are throwing on some tall tires that would change that ratio as per the speedometer.

Dave_mustang_50 · 06-11-2005, 11:18 PM

I`m gonna run thec6 til it dies then drop in an aod or swap to a manual. The Lentech street term. was recomended with a 3.70 or so rear gear. Any idea what i could expect from a 3.70 or 3.89 at 70mph? Tires are 255/60R15

bmxmon · 06-12-2005, 11:38 AM

http://www.dalesplace.com/htm/inform...calculator.htm I think this place would work for you, scroll down and you can enter in your info. ------- um sorry, i actually dont think that site will work, looking at it more, but this one might! http://www.mustang123.com/calculator...Calculator.asp

Dave_mustang_50 · 06-12-2005, 01:55 PM

That link is great. I hope its accurate though. Sounds like either the 3.70 or 3.89 will be perfect.

Looking at gear prices, the Summit ones are really cheap. Anyone heard anything good or bad about these. I had FMS on my last car and never had a problem

Rev · 06-12-2005, 04:09 PM

I run a 3.25 with my C-4 and 235/60/15's. That makes me cruise at 3000 rpm @ 70 mph. That's about as high rpm as I want to cruise.

If you later switch to an over-drive, you can easily use a much lower (numerically higher) rear axle. Then a 3.89 would be ideal IMHO.

Rev

My65Stang · 06-27-2005, 07:20 AM

What about an AOD trans? My next project is an AOD swap, new springs and rebuild the old 8". What ratio should I be looking for?

06-11-2005, 09:57 AM	#1
Dave_mustang_50 Registered Member Join Date: Aug 1999 Location: New Port Richey, Florida Posts: 483	Rear gear Ok, Im planning on ordering a rear gear for the Mach. The thing is, i`m not sure which gear it has without pulling it out. The car has a c6 and it shifts into 2nd at 50mph wot and into D around 90mph. The highest gear i have seen is a 3.50, but the car came with a 3.00 according to the warranty plate. Right now im thinking of either the 3.70 or the 3.89. This isnt a highway car, but i`d like to be able to cruise 80. anyone have any experience with the c6 and these gears with a 351? __________________ 1969 Mach 1 351C with a c6(for now) Sold 92 Rag Top GT Procharged & intercooled DSS 331 LC Holley Systemax 2 Intake, Edelbrock RPM Heads,E 303 ,blow thru air meter, race bypass, 42 pph injectors,65mm tb,1.7 rr, Mac long tube headers w/off road H pipe, Force 2 catback, TKO,Pro 5.0, K&N, Alum DS,3 core radiator, subframe connectors,3.73`s, Nitto DR`s and a Heavy Foot.

06-11-2005, 08:01 PM	#2
Phillyfanfrombirth Registered Member Join Date: Dec 2004 Location: South Central PA Posts: 358	Re: Rear gear Is there a tag on the front of the pumpkin? The tranny won't matter much since it doesn't have an overdrive... everything will be 1:1. 3.89s are a little steep for street use, for better driability I'd say 3.50s would be a good choice unless you are throwing on some tall tires that would change that ratio as per the speedometer.

06-11-2005, 11:18 PM	#3
Dave_mustang_50 Registered Member Join Date: Aug 1999 Location: New Port Richey, Florida Posts: 483	Re: Rear gear I`m gonna run thec6 til it dies then drop in an aod or swap to a manual. The Lentech street term. was recomended with a 3.70 or so rear gear. Any idea what i could expect from a 3.70 or 3.89 at 70mph? Tires are 255/60R15 __________________ 1969 Mach 1 351C with a c6(for now) Sold 92 Rag Top GT Procharged & intercooled DSS 331 LC Holley Systemax 2 Intake, Edelbrock RPM Heads,E 303 ,blow thru air meter, race bypass, 42 pph injectors,65mm tb,1.7 rr, Mac long tube headers w/off road H pipe, Force 2 catback, TKO,Pro 5.0, K&N, Alum DS,3 core radiator, subframe connectors,3.73`s, Nitto DR`s and a Heavy Foot.

06-12-2005, 11:38 AM	#4
bmxmon Registered Member Join Date: Mar 2004 Location: Minnesota Posts: 950	Re: Rear gear http://www.dalesplace.com/htm/inform...calculator.htm I think this place would work for you, scroll down and you can enter in your info. ------- um sorry, i actually dont think that site will work, looking at it more, but this one might! http://www.mustang123.com/calculator...Calculator.asp __________________ Alex

06-12-2005, 01:55 PM	#5
Dave_mustang_50 Registered Member Join Date: Aug 1999 Location: New Port Richey, Florida Posts: 483	Re: Rear gear That link is great. I hope its accurate though. Sounds like either the 3.70 or 3.89 will be perfect. Looking at gear prices, the Summit ones are really cheap. Anyone heard anything good or bad about these. I had FMS on my last car and never had a problem __________________ 1969 Mach 1 351C with a c6(for now) Sold 92 Rag Top GT Procharged & intercooled DSS 331 LC Holley Systemax 2 Intake, Edelbrock RPM Heads,E 303 ,blow thru air meter, race bypass, 42 pph injectors,65mm tb,1.7 rr, Mac long tube headers w/off road H pipe, Force 2 catback, TKO,Pro 5.0, K&N, Alum DS,3 core radiator, subframe connectors,3.73`s, Nitto DR`s and a Heavy Foot.

06-12-2005, 04:09 PM	#6
Rev Registered Member Join Date: Nov 1998 Location: Houston, Tx. Posts: 3,887	Re: Rear gear I run a 3.25 with my C-4 and 235/60/15's. That makes me cruise at 3000 rpm @ 70 mph. That's about as high rpm as I want to cruise. If you later switch to an over-drive, you can easily use a much lower (numerically higher) rear axle. Then a 3.89 would be ideal IMHO. Rev __________________ '66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe

06-27-2005, 07:20 AM	#7
My65Stang Registered Member Join Date: Jun 2005 Location: Akron, Ohio Posts: 6	Re: Rear gear What about an AOD trans? My next project is an AOD swap, new springs and rebuild the old 8". What ratio should I be looking for?

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