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#1
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SWAPPING OUT A 3.55 POSI - HOW MUCH SHOULD I ASK FOR IT?
Still planning my rebuild, but I do know that I want to swap out my current 3.55 posi rear gears (code XH) for higher gears (lower numerical), probably 3.08s.
I don't want to keep the 3.55s, so, if I try to sell, my first question is, 1. what should I ask for it? Also, 2. what should I expect to pay for a 3.08 posi? Just trying to get a ball park feel for what it should cost me . . . Thanks, guys, Harry
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REDGOAT 70 1970 GTO 400/350 TH400 |
#2
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hmmm. i have a posi 308 sitting in the garage...its been sitting for a while (surface rust), i havent looked inside in a while but its tight...maybe we could trade...i would keep it if i were you...IF you can find one, they go for about $300. ...is yours and A body(springs) or F body ...leafs...mine is leafs
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'74 formula 400, w/shaker (3 scoops) black deluxe interior, '70 406 balanced assembly, .30 trw slugs, moly rings, 4x heads 2.11/1.77 stainless valves, ra 4 cam, e-rpm intake, holley 750 vac. sec, msd hei, hooker headers w/ dual 3'' flowmaster 50 series ending at axle, t400 w/ GM6 convertor, transgo shift kit, b&m starshifter, 3.08 gears, centerlines, 265/50-15 bfg's rear and 235/60-15 front...yes im over cammed but it is still very fun... |
#3
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form406, I have an A body (70 GTO). It originally came with 3.23s, but they got swapped for a 3.55.
So, $300 for a 3.55 diff. I wonder how much a 3.08 rear gear goes for? Yes, other people have said to keep the 3.55s, the problem is, where? My wife would not like the bedroom, outside would not be good.
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REDGOAT 70 1970 GTO 400/350 TH400 |
#4
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im talking the whole rear end too...id say $300. and up...and i mean keep in your car forget the 308...
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'74 formula 400, w/shaker (3 scoops) black deluxe interior, '70 406 balanced assembly, .30 trw slugs, moly rings, 4x heads 2.11/1.77 stainless valves, ra 4 cam, e-rpm intake, holley 750 vac. sec, msd hei, hooker headers w/ dual 3'' flowmaster 50 series ending at axle, t400 w/ GM6 convertor, transgo shift kit, b&m starshifter, 3.08 gears, centerlines, 265/50-15 bfg's rear and 235/60-15 front...yes im over cammed but it is still very fun... |
#5
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i built a 8.2 BOP out of my 68 tempest,
spent 175ish on 3.55 ring and pinion gear 459 on a aubrun pro series 100 on a bearing kit, spacers, etc. a shop would cost you 300 to install, or so ive heard, it dont take a rocket scientist to press bearings!! if you wanted to change gears, 300 is about right. Brian
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i had a chevy engine once, then i got a pontiac |
#6
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Are you talking about selling the whole rear or the carrier?
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-- James Work '67 GTO Convertible "Koerner Built 413 500 hp with a Victor!.. I'll run a stock intake." '75 Formula 400 - Daily Driver - Running with my Home Built 455 and TH400 Details here: http://forums.maxperformanceinc.com/...d.php?t=588372 |
#7
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i was talking whole used rear and his lady must be talking about a whole rear cause you could hide just the carrier (put in bowling ball bag) ...total rebuild with new gears and parts with labor would be around $600. to 700. ...
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'74 formula 400, w/shaker (3 scoops) black deluxe interior, '70 406 balanced assembly, .30 trw slugs, moly rings, 4x heads 2.11/1.77 stainless valves, ra 4 cam, e-rpm intake, holley 750 vac. sec, msd hei, hooker headers w/ dual 3'' flowmaster 50 series ending at axle, t400 w/ GM6 convertor, transgo shift kit, b&m starshifter, 3.08 gears, centerlines, 265/50-15 bfg's rear and 235/60-15 front...yes im over cammed but it is still very fun... |
#8
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I bought a 4.11 rear with strange axles and a detroit locker for 300$ and it works great. I would guess 250 to 350. Franks pontiac parts sells them for around that price.
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72 Lemans |
#9
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Well I dont know... My wife wouldnt be too happy about an extra Bowling Ball laying around either. My average doesn't go up no matter how much I bowl for some reason...
Dream if you meant the whole rear, well then I'm nearby, and I'd like to talk to about the 3:55 rear. What condition is it in? I have a Highway posi, that I'm running and dont need the tall gears..And I dont cruise my car on the open road. I can smoke the tires in it easily even if it's a 2.73. Its an 8.5 out of a 71 OLDS. A possible/partial trade is ok since I dont need an extra rear laying around either. My wife only wants me looking at hers! Its got a new pinion and new axle bearings and seals...less then 100 miles on . The 2.73.. not my wife's...
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-- James Work '67 GTO Convertible "Koerner Built 413 500 hp with a Victor!.. I'll run a stock intake." '75 Formula 400 - Daily Driver - Running with my Home Built 455 and TH400 Details here: http://forums.maxperformanceinc.com/...d.php?t=588372 |
#10
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OK, now I have to show my ignorance . . . . I thought the "rear end" meant the entire axle as well as the gears that convert from the drive shaft to the wheels . . . .
So, then the "carrier" is the housing in the middle of the axle, and that's all I swap out? The code XH is on the axle on the driver side, that's why I thought the whole axle gets swapped out . . . . . I wanted to go with a lower numerical for lower rpm/better HW mileage . . .
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REDGOAT 70 1970 GTO 400/350 TH400 |
#11
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if all you want is the highway rpm's i would go to the junkyard and pull a tempest/lemans rearend out. they bolt in simply enough and theyll only cost ya 100-150$ + upper bushings there usually open 8.2 or 8.5 ring with 2.73/ 2.56. if your looking for out of the hole performance then build a decent posi..
but then again i scrape the bottom of the barrel for pennys!
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i had a chevy engine once, then i got a pontiac |
#12
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The carrier is the thing inside the thing in the middle
It holds (carrys) the gears. The axles get pushed into that as you bolt them in on the backing plate. But let me know if you want to sell it (your entire rear end) or swap me for my freeway gears (Entire Rear end) . I'm interested depending on the condition.
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-- James Work '67 GTO Convertible "Koerner Built 413 500 hp with a Victor!.. I'll run a stock intake." '75 Formula 400 - Daily Driver - Running with my Home Built 455 and TH400 Details here: http://forums.maxperformanceinc.com/...d.php?t=588372 |
#13
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posi rear ends are hard to find in the bay area because everyones looking for them...but if you can find one in a pick your own yard they are around $100-$150.
swapping whole rearends is a bit easier and less costly than building internally assuming you find a decent one...did you call gmsports in sj? last time i talked to them all they had were whole posi 273's (dont know body type)and they were bit pricey, but easy access...ill poke around the richmond yard...rebuilding a new rear end is about $600.-$700. but well worth the price...
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'74 formula 400, w/shaker (3 scoops) black deluxe interior, '70 406 balanced assembly, .30 trw slugs, moly rings, 4x heads 2.11/1.77 stainless valves, ra 4 cam, e-rpm intake, holley 750 vac. sec, msd hei, hooker headers w/ dual 3'' flowmaster 50 series ending at axle, t400 w/ GM6 convertor, transgo shift kit, b&m starshifter, 3.08 gears, centerlines, 265/50-15 bfg's rear and 235/60-15 front...yes im over cammed but it is still very fun... |
#14
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18 months ago I sold an XH rear for 650 easily, should of asked more.
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#15
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What kind of ride can you expect when going from 3.55s to 3.08s?
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REDGOAT 70 1970 GTO 400/350 TH400 |
#16
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#17
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70 Dream:
One other thing to consider, is whether or not the diff. in your car is the original and correct for the car. If you find that it is, you might decide to simply change the gears and install a posi. and keep the same axle housing with all the "correct" markings. I don't know if your into that or not, just thought I would mention that consideration.
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____________________________________ "I work in high speed aluminum tubing." |
#18
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3.90 is necksnapping, 3,55 is coffeespilling, 3.08 is zzzzzzzzzz.
I´ve changed from 3.55 to 3.07 in my 1966 Tripower GTO, great cruising gears, saves fuel too. |
#19
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my 308 isnt bad with 50 series tires... and does help with mileage..might not help in the 60 foot times but ill catch you on the far side...
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'74 formula 400, w/shaker (3 scoops) black deluxe interior, '70 406 balanced assembly, .30 trw slugs, moly rings, 4x heads 2.11/1.77 stainless valves, ra 4 cam, e-rpm intake, holley 750 vac. sec, msd hei, hooker headers w/ dual 3'' flowmaster 50 series ending at axle, t400 w/ GM6 convertor, transgo shift kit, b&m starshifter, 3.08 gears, centerlines, 265/50-15 bfg's rear and 235/60-15 front...yes im over cammed but it is still very fun... |
#20
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I have a set of new in the box 3.08 12 bolt gears..paid $200 will sell for $150...
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