What ratio rear end should I use?
02-02-2011, 02:16 PM
#11
5th Gear Member
Join Date: Jun 2005
Location: So. California
Posts: 2,258
Im running an AOD with 4.11s. flat out sucks on the streets. 1st gear is a waste, better off starting in second and 80 mph is pretty tough on the rpms. Im trying to decide to switch to either 3.50's or 3.73's
02-02-2011, 07:06 PM
#13
4th Gear Member
Join Date: Jun 2006
Location: Upland, California
Posts: 1,246
02-02-2011, 10:52 PM
#15
3rd Gear Member
Join Date: Aug 2010
Location: tn
Posts: 889
02-03-2011, 10:21 AM
#17
3rd Gear Member
Join Date: Apr 2008
Location:
Posts: 939
Gearing is a much debated and much opinionated subject. Here's my opinion:
Ther is no perfect gear. Unless the car is purpose built, any gear you choose will have plusses and minuses.
Consider where you're going to spend most of your time in 5th gear - cruising the back roads at 55-60? Or cruising the highway at 75-80? Pick the rear end gear that will put you at the bottom of your power band at that speed. The lower gears will take care of themselves.
I hear a lot of people say "First gear will be useless". For most street set ups, that statement just isn't true. The differance in shift point speeds is <2mph between a 3.27 gear and 3.73 gear. I use a 3.55 rear gear and 3.29 1st gear. I use first all the time. I prefer a low first gear; makes it real easy to drive in traffic and parking lots without slipping the clutch.
As for the trans, if you're carefull with a stok T5, it will last. But lots of torque and some clutch dumps will kill it pretty quickly. Step up to an aftermarket gear set in the stock case- like Levy Racing or G-Force. Cheaper than a TKO, better than stock. It's more money now, but saves money, time, and work in the long run.
Ther is no perfect gear. Unless the car is purpose built, any gear you choose will have plusses and minuses.
Consider where you're going to spend most of your time in 5th gear - cruising the back roads at 55-60? Or cruising the highway at 75-80? Pick the rear end gear that will put you at the bottom of your power band at that speed. The lower gears will take care of themselves.
I hear a lot of people say "First gear will be useless". For most street set ups, that statement just isn't true. The differance in shift point speeds is <2mph between a 3.27 gear and 3.73 gear. I use a 3.55 rear gear and 3.29 1st gear. I use first all the time. I prefer a low first gear; makes it real easy to drive in traffic and parking lots without slipping the clutch.
As for the trans, if you're carefull with a stok T5, it will last. But lots of torque and some clutch dumps will kill it pretty quickly. Step up to an aftermarket gear set in the stock case- like Levy Racing or G-Force. Cheaper than a TKO, better than stock. It's more money now, but saves money, time, and work in the long run.
02-04-2011, 02:38 AM
#19
Thread Starter
Join Date: Jan 2011
Location: california
Posts: 37
So I found this on Bruce Couture's modern driveline website:
"For a 1965 - 1966 Mustang we recommend a T-5 transmission for engines making under 450hp. The T-5 fits much better than a larger TREMEC TKO due to clearance issues with the transmission tunnel. TKO transmissions can be installed but it requires modifying the transmission tunnel. A T5 swap in these cars is straight forward whether swapping an automatic or a Toploader. Even the inline-6 transmissions can be swapped with a T5. The only modification needed to install a T-5 is to clearance the right side of the shifter opening by 3/8"."
http://www.moderndriveline.com/Techn...ic_mustang.htm
I guess I'm just wondering why everyone seems to think that the T-5 won't put up with the abuse that people give it?
"For a 1965 - 1966 Mustang we recommend a T-5 transmission for engines making under 450hp. The T-5 fits much better than a larger TREMEC TKO due to clearance issues with the transmission tunnel. TKO transmissions can be installed but it requires modifying the transmission tunnel. A T5 swap in these cars is straight forward whether swapping an automatic or a Toploader. Even the inline-6 transmissions can be swapped with a T5. The only modification needed to install a T-5 is to clearance the right side of the shifter opening by 3/8"."
http://www.moderndriveline.com/Techn...ic_mustang.htm
I guess I'm just wondering why everyone seems to think that the T-5 won't put up with the abuse that people give it?
02-04-2011, 11:16 PM
#20
2nd Gear Member
Join Date: Nov 2010
Location: Ontario
Posts: 493
An excellent post above by bOB....
Lots of people really "fear the gear" these days...My brother has a 67 fastback that had a toploader 4 speed and a 3:1 rear end...We swapped in a T-5 trans and a set of 4:11s in the rear end..It runs about the same rpms on the highway now as it did before the swap..People will say the 4:11s are way to low for a driver but yet wouldn't bat an eye at the 3:1 setup...
Having said all of that your 408 should have lots of torque and you could gear it fairly high and still have good acceleration..
Lots of people really "fear the gear" these days...My brother has a 67 fastback that had a toploader 4 speed and a 3:1 rear end...We swapped in a T-5 trans and a set of 4:11s in the rear end..It runs about the same rpms on the highway now as it did before the swap..People will say the 4:11s are way to low for a driver but yet wouldn't bat an eye at the 3:1 setup...
Having said all of that your 408 should have lots of torque and you could gear it fairly high and still have good acceleration..