[RR67GTO]

Good morning. I'm almost done with a healthy 455 that I am going to put into my 68 Firebird that now has the tired 350 i it backed by a TH350. I installed new leafe springs and need to get sub frame connectors which are on the way.

The problem I'm having is with the rear end. It has the 8.2 open 256 geared unti that came from the factory. And, this just ain't gonna make it. So, I set out looking for a 12 bolt to stick in it but the two I found cost big bucks.

So, I need some advice as to what would be the best way to go with this, and I can't buy a new currie or anything. Can a A body 12 be resized at a reasonible price ? Or, what about the same thing using a nine inch ? There are a fair amount of othercars that can provide another 8.2 if I wanted to install a posi and run 355 gears i it. But as hard as they are to find for BOP, I would like to stay around the 323's or so. That's why Chevy was an idea I had until I saw what those guys valued them at. The car will be driven on the street most of the time. Although pretty hard sometimes as I like messing with the kids in the area. And on a few weekends I will go to the track with it.

I know I'm asking for a lot, but even to know what others are doing dealing with hte same problem I'm having would be a step in the right direction. Thanks again, and have a wonderful day friends. Much of what I learn hear has kept my project moving right along.

Mike

[RR67GTO]

Good morning. I'm almost done with a healthy 455 that I am going to put into my 68 Firebird that now has the tired 350 i it backed by a TH350. I installed new leafe springs and need to get sub frame connectors which are on the way.

The problem I'm having is with the rear end. It has the 8.2 open 256 geared unti that came from the factory. And, this just ain't gonna make it. So, I set out looking for a 12 bolt to stick in it but the two I found cost big bucks.

So, I need some advice as to what would be the best way to go with this, and I can't buy a new currie or anything. Can a A body 12 be resized at a reasonible price ? Or, what about the same thing using a nine inch ? There are a fair amount of othercars that can provide another 8.2 if I wanted to install a posi and run 355 gears i it. But as hard as they are to find for BOP, I would like to stay around the 323's or so. That's why Chevy was an idea I had until I saw what those guys valued them at. The car will be driven on the street most of the time. Although pretty hard sometimes as I like messing with the kids in the area. And on a few weekends I will go to the track with it.

I know I'm asking for a lot, but even to know what others are doing dealing with hte same problem I'm having would be a step in the right direction. Thanks again, and have a wonderful day friends. Much of what I learn hear has kept my project moving right along.

Mike

[Tom]

Years ago I installed a Posi rear from a 64 Chevelle(10 bolt)in my 68 Camaro by just welding on spring perches.The early 64-66 and maybe 67 A body rears are the same width as the 67-69 Camaro/Firebirds.The 68-72 A body rears are only 1/2"/side wider than the earlier ones.You have to cut off the coil spring and control arm mounts and have a set of perches welded on.I even left the cast in upper bushings in place on the center section.

Tom

[Ken K]

I think a 69-70 Mustang nine inch is a bolt in, I have heard even the spring perchs are in the right place. You can also use a 72-74 Nova-Ventura and the other clones in that body style, they use a 8.5 inch 10 bolt which is almost as strong as a 12 bolt and the gears are easy to get for them.

[RR67GTO]

Thanks friends for the information. Always keep all the info I get in my files. And use much of it. Today (SundaY) it was nice so I decided to take my Pontiac Bike for a ride and ended up stopping at one of my fav-orite places. My local U-Pull-it junk yards that does like buying older junk cars and has a fair amount of Pontiacs. Prices are posted for items on a board, so you know what you pay before getting down and dirty.

I looked around and all the first and second gen Firebirds like I have for the past five years. Most of which are still being parted for small things. Anyway, I say a car that was not their a few weks ago whrn I was last there. It's a well runted and dented 69 400 FB. So, I decided to check the rear end out and Sheeeeesh, I counted twelve bolts on a multi spring car. Nawww, I had to count wrong because I never ware my glasses like I should. However, after using my fingers and as I toucked each bolt sure enough, it was a trans planted 12 bolt open rear end. So, because the rear ends are not posted with prices because to may to have a single price I asked what they wanted for it. The answer was Oh Mike ya mean the chevy 12 bolt ? Well, we will have to ask the owner on Tuesday. Anyway, I get along good with these people and they treat me right. However, for months I've asked them to call if they found one of these. Hmm anyway, I'll see what the boss wants. And, I'll let you know. Thanks again for all the help. Pardon the bad spelling, it's late, I'm tired and I have more projects going on than time. What a wonderful life. And, she even baked cookies today [img]/infopop/emoticons/icon_smile.gif[/img] Good day and best wishes. < Mike >

[Colorado Bill]

On the subject of cross-brand mutants: I couldn't find a Mustang 9" to replace the 10 bolt in my '72 Nova, but I discovered that the 8.75" from a Mopar A body would fit--I got one from a 340 Duster. I don't know how the Mopar would hold up behind a 455, but I haven't had any problems with my 400 (Pontiac) and slicks. I'm trying to remember now why I didn't just build the 10 bolt. I guess because I wanted to be able to change gears by swapping center sections. And we did everything the hard way on that car.

[1972_GTO]

Mike,

The man that you need to talk to is ol' Pinion head. Check the link below for a very similar conversation that I had with him about the same subject.

http://performanceyears.com/ubb/Foru...ML/001218.html


Good luck!