'71 Ring and Pinion Swap: 2.56 to 3.55??

Hi, I have a '71 V8 Nova with the original 10-bolt with a 2.56 rear gear. With this high of a gear from the factory, will I need a new carrier to upgrade to a 3.55 ring and pinion?

i think you will have to swap, but if its a 8.2 rear dont bother , try finding a 73-75 nova rear, i know for sure these are 8.5 and will have 3.08 gears or if you want you could use a 8.8 mustang rear, but would take some welding and drive shaft mods to work.

Hi, I have a '71 V8 Nova with the original 10-bolt with a 2.56 rear gear. With this high of a gear from the factory, will I need a new carrier to upgrade to a 3.55 ring and pinion?

Yep, either a new carrier or a ring gear spacer.

I think from 1970 to 1975 all were 8.5 inch.. So, he should only need a new ring and pinion..

i think you will have to swap, but if its a 8.2 rear dont bother , try finding a 73-75 nova rear, i know for sure these are 8.5 and will have 3.08 gears or if you want you could use a 8.8 mustang rear, but would take some welding and drive shaft mods to work.

I think from 1970 to 1975 all were 8.5 inch.. So, he should only need a new ring and pinion..

8.5 started with 72 models, its possible some late production 71's had them also.

Sounds like to me, the 8.2 will be plenty good for what Goldie wants to do. Doesn't sound like hes going to be throwing big power at it. Maybe I'm wrong, Goldie?

I stand corrected.. In any case, here's all the info you may need that you can refer too goldie_71 http://novaresource.org/axle.htm

8.5 started with 72 models, its possible some late production 71's had them also.

Sounds like to me, the 8.2 will be plenty good for what Goldie wants to do. Doesn't sound like hes going to be throwing big power at it. Maybe I'm wrong, Goldie?

8.5 started with 72 models, its possible some late production 71's had them also.

Sounds like to me, the 8.2 will be plenty good for what Goldie wants to do. Doesn't sound like hes going to be throwing big power at it. Maybe I'm wrong, Goldie?


Nah, I'm not going to be beating on it at all...I have way too many years and too much money in this car to mess it up being stupid. The thing is just such a dog with the 2.56's. It's so bad that it starts opening the 4bbl on the interstate to keep it at 70 mph. No wonder the gas mileage is so horrible.

I'm pretty sure the car has an 8.2 rearend. I don't have the car handy, or I'd go measure the centersection. But with the 8.2, I'd still have to swap to at least a 3.08 carrier?

The 8.2" will be fine for most mild/moderate street cars...
Remember, with street times traction is limited...so without sticky tires, there isn't as much stress put on parts. In other words, the tires break loose before the rear end will.

That being said, you have a few different routes you can take...

First would be to get an ring and pinion set with a "Thick" ring gear. To compensate for the differences between a series 2 (yours) and series 3 carrier, a few gear companies sell "thick" ring gears. Using a thick ring gear allows for numerically higher gear ratio's to be used.
They are typically a little more ****$, but if you look around you'll find a good price. Here is an example of a strange set of 3.73's for a series 2 carrier, via summit:
http://store.summitracing.com/partdetail.asp?part=STR%2DRS01882373C&view=16383&N=700+
Call 'em up and tell them what you're looking for--they'll set you up right.

Second choice is a ring gear spacer--it does the same thing as a "thick" ring gear, but lets you use a regular gear and the extra thickness comes from a spacer. This is NOT very desireable, IMO...The more shims you add, the more potential of a problem you'll introduce. I know people who have used 'em with good results, but I'd rather NOT!
Here's one from Summit:
http://store.summitracing.com/partdetail.asp?autofilter=1&part=MRG%2D900A&N=700+115&autoview=sku

A third option would be to look around for a used series 3 carrier so you can use the gears you'd like. They are CHEAP, as they are quite common and available. Look around local junk yards, diff. shops, and swap meets. I'd avoid ebay if you can--is costs too much for the parts, then get ripped for shipping as well.
This will cost you ****$ for the new carrier, as well as new bearings and races...but will give you the right carrier with NO shims, or added expense of "thick" gears.

Final choice, search you local yards for a complete rear end (8.5, 12-bolt, etc) that will fit in your car. '72 and up nova's had the stronger 8.5...they're easy to find and cheap.
My local yards ask $150 for these old rear ends, no matter what brakes, gears, and carrier are inside. Posi units are easily found in mid/late 70's Camaro's as well. I bought one from a swap meet for $40 for my '72. You might get fortunate and find the correct rear, with the gears you desire, and posi for a great price...and with new bearings and seals you'd have a clean and stronger rear end.

Yea I agree. best/cheapest option in my mind would be to scour the junkyards for a suitable complete rear and just swap it out. posi or not.

Buying gears and then paying someone to install and set them up correctly would probably cost twice as much as a junkyard unit... if you can find one.

The 8.2" will be fine for most mild/moderate street cars...
Remember, with street times traction is limited...so without sticky tires, there isn't as much stress put on parts. In other words, the tires break loose before the rear end will.

That being said, you have a few different routes you can take...

First would be to get an ring and pinion set with a "Thick" ring gear. To compensate for the differences between a series 2 (yours) and series 3 carrier, a few gear companies sell "thick" ring gears. Using a thick ring gear allows for numerically higher gear ratio's to be used.
They are typically a little more ****$, but if you look around you'll find a good price. Here is an example of a strange set of 3.73's for a series 2 carrier, via summit:
http://store.summitracing.com/partdetail.asp?part=STR%2DRS01882373C&view=16383&N=700+
Call 'em up and tell them what you're looking for--they'll set you up right.

Second choice is a ring gear spacer--it does the same thing as a "thick" ring gear, but lets you use a regular gear and the extra thickness comes from a spacer. This is NOT very desireable, IMO...The more shims you add, the more potential of a problem you'll introduce. I know people who have used 'em with good results, but I'd rather NOT!
Here's one from Summit:
http://store.summitracing.com/partdetail.asp?autofilter=1&part=MRG%2D900A&N=700+115&autoview=sku

A third option would be to look around for a used series 3 carrier so you can use the gears you'd like. They are CHEAP, as they are quite common and available. Look around local junk yards, diff. shops, and swap meets. I'd avoid ebay if you can--is costs too much for the parts, then get ripped for shipping as well.
This will cost you ****$ for the new carrier, as well as new bearings and races...but will give you the right carrier with NO shims, or added expense of "thick" gears.

Final choice, search you local yards for a complete rear end (8.5, 12-bolt, etc) that will fit in your car. '72 and up nova's had the stronger 8.5...they're easy to find and cheap.
My local yards ask $150 for these old rear ends, no matter what brakes, gears, and carrier are inside. Posi units are easily found in mid/late 70's Camaro's as well. I bought one from a swap meet for $40 for my '72. You might get fortunate and find the correct rear, with the gears you desire, and posi for a great price...and with new bearings and seals you'd have a clean and stronger rear end.

You know what makes me sick.....I used a 63k mile 4-door '72 for parts..and about the only thing I didn't get off of it was the rearend. I just assumed that it was the same rearend as my '71. Man! :mad:

So basically any of the later model Camaro/Nova rears are a direct bolt-up?

You know what makes me sick.....I used a 63k mile 4-door '72 for parts..and about the only thing I didn't get off of it was the rearend. I just assumed that it was the same rearend as my '71. Man! :mad:

So basically any of the later model Camaro/Nova rears are a direct bolt-up?


Try to get a nova rear if you can, I think the camaro rears are a little wider.
72-74 Nova rear would be perfect, I'm not sure about 4th gens.

72-74 Nova rear would be perfect, I'm not sure about 4th gens.

The 4th gen rears are a direct bolt-in swap as well. However, some 76-79's have the weaker 7.5" 10-bolts. In general, most factory V8 cars used the 8.5's while 6-cyl cars used the 7.5's. But there are exceptions and a swap could have taken place in the past so be sure to check. For example, I found an 8.5" rear in a 78 6-cyl car that in theory should have had a 7.5.

Also note that the rear brake lines were routed a little bit differently starting sometime around 75 or 76. The Tee fitting at the end of the flex line was moved from a bolt-on bracket on the diff cover to a welded-on bracket on the driver side axle tube. The 4th gen flex line probably won't reach to the connection point on the 3rd gen body so you'd have to swap the 3rd gen bracket and steel brake lines that run along the axle tubes over onto the 4th gen axle assembly. The unused welded-on bracket could then be removed.

You might take a look at this thread I did on using a Ford Explorer 8.8 which is almost a direct bolt-in.

http://www.stevesnovasite.com/forums/showthread.php?t=47124&highlight=explorer

Dave