My Gear options?
#1
My Gear options?
I have a posi rear end stamped SB. Not positive of the actual year but it's after 69' bc it's not the axle with sealed bearings...my gears are 2.78 as of right now but heard that gear ratios were limited for this rear....could anybody confirm what gear ratuo options I have for this? I want some thing lower but I'm not taking it to the strip either it's a street car. Thanks
#2
Uh, does it have a 12 bolt cover or a 10 bolt cover?
I am guessing it's an O-Type 12 bolt since you said 2.78 ratio, and a 1970 version since it does not have sealed bearings, but that is just me guessing in a vacuum of information.
The O-Type 12 bolt has a very limited number of ratios, either aftermarket or factory. Currently the aftermarket ratios available from Richmond Gear are 3.42, 3.90, and 4.10 and these fit the 2.93-3.23 carrier only. Monzaz was making ring gear spacers for the 2.56-2.78 carrier but you would need to check with him to see if they are still available.
I am guessing it's an O-Type 12 bolt since you said 2.78 ratio, and a 1970 version since it does not have sealed bearings, but that is just me guessing in a vacuum of information.
The O-Type 12 bolt has a very limited number of ratios, either aftermarket or factory. Currently the aftermarket ratios available from Richmond Gear are 3.42, 3.90, and 4.10 and these fit the 2.93-3.23 carrier only. Monzaz was making ring gear spacers for the 2.56-2.78 carrier but you would need to check with him to see if they are still available.
Last edited by Fun71; April 15th, 2017 at 05:19 PM.
#3
Uh, does it have a 12 bolt cover or a 10 bolt cover?
I am guessing it's an O-Type 12 bolt since you said 2.78 ratio, and a 1970 version since it does not have sealed bearings, but that is just me guessing in a vacuum of information.
The O-Type 12 bolt has a very limited number of ratios, either aftermarket or factory. Currently the aftermarket ratios available from Richmond Gear are 3.42, 3.90, and 4.10 and these fit the 2.93-3.23 carrier only. Monzaz was making ring gear spacers for the 2.56-2.78 carrier but you would need to check with him to see if they are still available.
I am guessing it's an O-Type 12 bolt since you said 2.78 ratio, and a 1970 version since it does not have sealed bearings, but that is just me guessing in a vacuum of information.
The O-Type 12 bolt has a very limited number of ratios, either aftermarket or factory. Currently the aftermarket ratios available from Richmond Gear are 3.42, 3.90, and 4.10 and these fit the 2.93-3.23 carrier only. Monzaz was making ring gear spacers for the 2.56-2.78 carrier but you would need to check with him to see if they are still available.
#4
Only the 3.42 and 3.90 gears are available new. There is a modified Ford 8.8 posi available that is good quality that works with these gears. I too have a 2.78 open I need to replace. The gears and posi cost around $900, not cheap. The 3.42 is the max I would consider with a 3spd trans.
#5
Only the 3.42 and 3.90 gears are available new. There is a modified Ford 8.8 posi available that is good quality that works with these gears. I too have a 2.78 open I need to replace. The gears and posi cost around $900, not cheap. The 3.42 is the max I would consider with a 3spd trans.
#6
Fyi
Sell the rear end you have and put the rear end under it that you want. Your current carrier is only good for 2.56 and 2.78 gears. Put a 71-72 8.5" under it with the ratio you desire.
#8
#9
#10
#13
The 2.78 posi rear axle would make a great cruising gear ratio. What engine is in your car? Most 455 equipped cars have plenty of torque in combination with the 2.78 axle ratio to still light up the tires while retaining efficient highway travel. Even a 4-bbl, dual exhaust equipped 350 is still sprite with 2.78 gears, if you are not looking to go racing with the car.
#14
#15
The 2.78 posi rear axle would make a great cruising gear ratio. What engine is in your car? Most 455 equipped cars have plenty of torque in combination with the 2.78 axle ratio to still light up the tires while retaining efficient highway travel. Even a 4-bbl, dual exhaust equipped 350 is still sprite with 2.78 gears, if you are not looking to go racing with the car.
#16
Multiple sights show the 4.10's on back order, hopefully with them now in their catalog, they are being reproduced again. I also found these but look at the price! https://www.google.ca/url?sa=t&sourc...G1WfQ0s1JTpalw
#17
Multiple sights show the 4.10's on back order, hopefully with them now in their catalog, they are being reproduced again. I also found these but look at the price! https://www.google.ca/url?sa=t&sourc...G1WfQ0s1JTpalw
#18
The 2.78 posi rear axle would make a great cruising gear ratio. What engine is in your car? Most 455 equipped cars have plenty of torque in combination with the 2.78 axle ratio to still light up the tires while retaining efficient highway travel. Even a 4-bbl, dual exhaust equipped 350 is still sprite with 2.78 gears, if you are not looking to go racing with the car.
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