Just wondering if anyone knew of a rear end that I could swap into my 66 starfire without much custom work.
its a 66 starfire (hence the name heh)
Open rear end (one wheel wonder..)
I BELIEVE 2.73's? Im not 100% sure though.
Its got a 1970 Olds 88 455ci motor in it.
Id prefer posi and something thats a bit easier to get parts for.

anone have an idea? I can do the work I just dont want to make things like custom rear suspension points. not quite my forte. Oh yea and keeping it olds isnt nessesary, any GM will work, I just want a decent rear end with posi, and maybe say 308 or 323 gears.
thanks, starfire.

 

That is something I plan on doing on my '48 but haven't researched anything yet, of course, I will have to modify/fab some suspension perchs probably. Will be reading this thread closely...

 

Location please!

 

laramie wyoming

oh yea and I was reading into this on the oldspower forums, bt cant find the posts that I was reaing, otherwise I could probably answer my own question haha. Ill keep looking though. I believe moser makes one to fit, and currie? possibly also. it had to dow ith swapping in a gm 12bolt and just switching axels. Ill try to find mroe info.

 

I've got a 1968 Delta 88 complete rear end, non-posi. Then I have the 12 bolt posi unit out of a rear that I was told came out of a 1968 Full sized Olds. The casting number on the posi unit is 700 and it had 31 spline axles. It's got a tall ring gear on it right now, I believe 2.56. But I'm over here in Oregon, we have talked about wheels too. If this posi unit would fit something you had or could get your hands on shipping just the carrier wouldn't be too difficult. John

 

Actually thats almost what Ive been thinking of lately, It would be much easier to just swap in a new posi carrier. Im just trying to find one that works. I have a guy that gets gears at dealer prices, since hes a dealer hah. So gears arent a problem.

Ill keep ya in mind.

 

I'm sorry, but is the Starfire concidered a "full-size" car, or a "mid-size" like the 442? I'm in Pierre, South Dakota, and I have a 10 bolt posi for a mid-size GM A-body car if it would work???

 

its definietly full size. wheelbase is 123" and overall is 217"

its a land yacht, and most parts are compatible mechanically at least with the same years 88, 98, and maybe one other model Im forgetting

(I jsut got my owners manual from ebay today....score!)

so yea a a-body diff wouldnt work, at least not to my knowedge, only because it was just a few years before GM really started cross using products.
i believe at least, i ahvent found any other a body thigns compatible with mine.

 

oh yea and because my differential is an OLDSMOBILE 10 bolt, not a GM Corporate 10 bolt, I believe there is something different, at least thats what Ive read.

 

Track width is the hardest to match in a vehicle. If you get a rear axle from a car with a different track width the you may have trouble fitting the wheels in the wheelwells properly and the tires may rub on the inside or outside. Secondly, the bolt pattern could be different on the new axle. Third, the perches for the suspension may be in a different place. Have to check those things....

 

well, what Im TRYING to do, is to just get a diffrent carrier, one with posi, and set that in my pumpkin. then, I wouldnt have ANY fittment problems, because everyhting is the same, maybe I might need new axles, but that can be worked with. the 10bolt should be enough for this car. its got a 455 that once running perfect and i get some money, I am going to supercharge for a daily driver. make it a bit more fun off the line and such. its gunna be nothing fancy, just a nice looking daily driver with spunk ha.

 

Its not as easy as that with this type of rear....the posi unit and ring gear with pinion cannot be removed as a unit and swapped into your unit.

 

darnit I was afraid of that.

do you ahve any suggestions? Or just basically fabricate mountings for a gm corporate 10 bollt of bigger ha.

any ideas though?

 

You have 2 options....find a rear with the posi and gear ratio you want. The factory unit in 66 is actually a Pontiac unit. Look for a big car Pontiac from 65 up to 70. In 67 Olds big cars used a 12 bolt year. You can also look to one of these cars to 1970 for the 12 bolt posi and change the whole rear assembly The other option is to find the posi unit and gear you want and have someone who knows what they are doing swap the thing into your rear.

 

so say a 68 or 69 bonneville with a posi rear end would work? because a guy ahs one right close to me that I may be able to pick up..
Id sorta like a posi with 3.08 gears, to have a bit more fun, but still keep RPMs low for higway driving, it will be a daily driver.
and instead of a bonni, I could look for a 67-70 big car Olds with posi? good because I know a guy who might have one.

just wondering, as Im not 100% sure on rear ends, I ahvent studied them very much yet, Im in the process of doing that, what do you mean by finding gears and a posi unit. Like find aftermarket gears for the stock 10 bolt, and then also a posi unit? and if so, WHERE could I find a posi unit for my rearend? gears mgiht also be hard, but Ill check. Id like to not have to swap out the whole rear end if I dont HAVE to but I will if nessesary, i realy want posi.
where could I look for a posi unti for a olds/pontiac 10 bolt?

and thanks alot for the help, I really appreciate it because this is an area im not competent in yet, Im still new to my oldsmobile period.

 

The Bonneville rear should work or the Olds 12 bolt from the big cars. I believe they are the same size. It is easier to swap the complete rear than it is to swap a ring and pinion and posi if you arent familiar with doing so. I dont believe there are any aftermarket/speed shop posi units or gears for the full size rears. Stuff can be bought for the Chevy Chevelle, 442,GTO rears. They are not the same as the full size cars. Look in junkyards, parts cars, and Ebay....you will find what you need.

 

you dont know at all by chance if a close year impala will work? jsut the ring/pinion? Im thinking not because thats GM A-body.

Oh well, time to start diving, I didnt buy this car becasue it was going to b easy.
I bought it cuz it was an olds with a BB and all the body lines I love. I know my car, came with posi as an option, and Im tlaking with a guy about a bumper and grill, ill see if his has posi....

thanks again for the help, its really appreciated dude.

your the reason I got outta the import market nice people that dont mind helping, and can still run down the track.

 

Chevy parts wont work at all....they use a C clip to hold the axles in while BOP rears use bolts.....the parts dont interchange and the rear out of an Impala wont line up....I have a 66 Sfire as well.....came with a 3:08 gear but no posi.

 

thats what I thought, I did some more research after I posted. and found out. Yea I took 2 diffs apart today, 1 chevy 10 bolt, and a 69 impala, nothing really like mine so no big deal. Ill search around until I find something, if not Ive been debating an air suspension, to put more force on one wheel or another, because ive seen that and it works almost as well or better, because it can be changed for every style, but thats also a bit mroe expensive.
thanks again.

 

66starfire;
Take it in steps. Remember your goal too. From your last post about air suspension it sounds like you are trying to bleed the last few tenths of a second from your 1/4 mile et's. I am no guru on this subject but have observed a lot of posts about it and the general consensus is taking it in steps becuase you are talking about traction not horsepower. Do you already have traction problems? If you don't then back up. Look at torgue converter stall speeds, rear differential axle ratio, and posi vs. peg leg. If you do have traction problems, what about tire type/inflation/size, boxed frames and conventional rear suspension improvements. Please don't take this the wrong way, as I said, I am no guru but keep focused on your goal.

 

Yep, I do have traction problems, my setup is a 455 BB from a 1970 delta 88.

it has F heads, and an E block I believe. I have an open diff with 2.73's, and stock 14" tires. Im not able to find thing to tub or narrow the rear, and fitting much bigger tires anyways would be a problem due to the tires would hit the fenders, and I dont want to cut. I want better all around traction without tubbing, narrowing, and my tranny is a TH-400 with a BM shift kit, new torque converter, I cant remember stall speed. Also a HEI ignition with aftermarket box (last owner installed that)
it does not like the one wheel on dry pavement, and wet or loose gravel type, it wont go anywhere, anyplace below 35-40ish, it spins with throttle.
I have also tried airing down and up the tires, airing them down just incrased wear, but new 15" wider tires/wheels are in order. This wont be a drag car by any means, but I DO want better traction for the holeshot when I take it. I am supercharging it, and I doubt that will help with traction. the good thing about air suspension, is that it can be adjusted to just give me a firmer ride, wich I like, but is also singularly adjustable for those drag races. a posi would make it just better to drive all around.
whew sorry for the long post. but yea Im pretty much at the rear end part of my buildup. I am buying HD springs for al 4 corners, and new suspension, its jsut not here yet.