I have 2.73 10bolt/8.2" open rear in my 69. new 383 making about 400hp with TH350. I've seen some references to a type 2, 3 and 4 rear end and i'm planning to increase the ratio while adding a powertrax NoSlip locker.

is it possible to change out the Ring and Pinion to 3.73 or 4.11 using the same rear end case?

I assume you meant a 10-bolt 8.2" rear? The answer is yes, it'll fit. Just get the 8.2 series 3 or 4 carrier to go with the gears you choose.

yes 10bolt 8.2". thank you.

If you have a 8.2" with 2.73's you will need to get a 3 series carrier or 4 series carrier depending on gears picked.
You could use a spacer but it's only a band-aid and I would NOT put any real faith in it.

I think (?) The Powertrax no-slip (http://store.summitracing.com/partdetail.asp?autofilter=1&part=PWT%2D92%2D0782%2D2805&N=700+115&autoview=sku) just replaces the spider gears in the stock carrier. If I'm right, then you'll only be able to make the 3.73 or 4.11 gears work with your current carrier if you run a spacer. Various opinions out there on how "bad" it is to run a spacer, but I'm with Doug -- I'd avoid it if at all possible.

So you either need to dig up a different (open?) carrier OR run a spacer (http://store.summitracing.com/partdetail.asp?autofilter=1&part=MRG%2D900A&N=700+115&autoview=sku) with your current setup. If it were me and I needed to dig up a different carrier anyway, I'd just look into running a "complete" new differential setup like the Eaton clutch-type posi (http://store.summitracing.com/partdetail.asp?autofilter=1&part=ETN%2D19603%2D010&N=700+115&autoview=sku)

http://www.powertrax.com/powertrax/images3/lockright6.jpg

The other thing worth mentioning is the 8.2 is not the strongest rear in the world, and that one is forty years old. Many believe it would be money better spent upgrading to a stronger rear than putting a thousand dollar investment into an 8.2.

Tha T350 trans can be done cheaper, it will give the same performance boost "off the line" without the highway rpm penalty. They were an available option with most Camaro engine combo's, and can use the stock shifter with a minor modification. The trans swap is also a boltin that you can do, where gear changes should be left to the pros.

Many believe it would be money better spent upgrading to a stronger rear than putting a thousand dollar investment into an 8.2.



I just purchased all the parts necessary to change over my 2:73 to a Eaton 3:55 posi for $660.00 The advice I got was as long as I was running street tires and not hanging around the dragstrip, the 10 bolt 8.2 would stand up fine to my ZZ/4. We'll see :beers: Kevin

Kevin, you'll have to share how much MPG you get after the exchange compared to the orig?

capt

I just purchased all the parts necessary to change over my 2:73 to a Eaton 3:55 posi for $660.00 The advice I got was as long as I was running street tires and not hanging around the dragstrip, the 10 bolt 8.2 would stand up fine to my ZZ/4. We'll see :beers: Kevin

It will hang pretty good for a while. (see below, all on 8.2" 3.73,and Eaton Posi pushing MT DR's)

.... Tha T350 trans can be done cheaper, it will give the same performance boost "off the line" without the highway rpm penalty. They were an available option with most Camaro engine combo's, and can use the stock shifter with a minor modification. The trans swap is also a boltin that you can do, where gear changes should be left to the pros.

Jim, rather then the rear, what trans modification are you referring to the T350 to help the low end? i have T350 in now with gears 2.52, 1.52, 1.0. any idea on cost?

Jim, rather then the rear, what trans modification are you referring to the T350 to help the low end? i have T350 in now with gears 2.52, 1.52, 1.0. any idea on cost?


Steve, it sounds like Jim thought you probably had a powerglide.

I'd skip the powertrax unless you like listening to a lot of rear end noise during slow speed turns/parking lot manuvers and people looking at you like your car is breaking. These units make a pretty loud clicking noise as they ratchet when you turn.

As suggested earlier the Eaton clutch type posi is nice as well as the Detroit trutrac wich is a gear driven type posi. You'll just need to get the correct series case to go with whatever gear ratio you decide on.

As suggested earlier the Eaton clutch type posi is nice as well as the Detroit trutrac wich is a gear driven type posi. You'll just need to get the correct series case to go with whatever gear ratio you decide on.

I like the TrueTrac as well, but they don't offer one for the 8.2" rear as far as I know (?), so he'd need to step up to an 8.5" rear if he wants a TrueTrac....

I like the TrueTrac as well, but they don't offer one for the 8.2" rear as far as I know (?), so he'd need to step up to an 8.5" rear if he wants a TrueTrac....

You are correct, I didn't even think of it not being available for the 8.2.

Kevin, you'll have to share how much MPG you get after the exchange compared to the orig?

capt

Unfortunatly, I never drove the car after buying it enough before I tore it apart last November. It's looking like i won't be on the road until late this year. Just too many things to do.....:(

i get no clicking from my powertrax lock right. The only thing strange which is kinda cool is when i am going around a corner and it shifts, it easily chips the tires.