Hey guys, my '55 was a drag car in the '60s & '70s, and it has a '57 Pontiac rear with a 5.13 posi. (it may be a spool, or welded spiders, I dunno, but I've put about 300 street miles on it and haven't noticed any chirping or anything around corners) In case you don't know, a 5.13 isn't the most street friendly gear out there. I'd like to swap gears, but I don't know where to find a new gear set. Do companies like Richmond make new gears, or will I have to hunt for some used gears? I'm thinking I'd like something around a 3.90 ratio. Thanks in advance guys! Steve
If you search the forum, there may be some old posts on this - I know it was discussed. But I believe Richmond does make a few gear sets for it, from what I remember - best bet is to call or e-mail them I suppose. Outside of that, it's hit the salvage yard. Most of your '57s are open rears, a '57 Posi was made but it's so rare I have had guys argue with me that it doesn't exist. You may want to count the splines on your axles first. One relatively easy modification was to put a '58-'64 posi into the '57 housing - it fits with a little grinding, but requires custom axles or the wider, newer ones be shortened. I can't remember if the gears themselves swap between the '57 and the '58-'64 unit. The '58-up posi was a lot easier to find - That gear set you have, if you don't keep it, would probably pay for a whole new rearend in the car -
57 and 58 both use 29 spline axles. 58 was the first year for posi but the carrier will go in a 57 housing ok and accept the 57 axles as 57 and 58 had exactly the same length/spline count axles.. '59 to '64 all used longer, 31 spline axles. I've shortened up the shortest of the factory 31 spline axles by cutting off the ends [61-64 Olds] to work with my 57 housing with a 64 posi center section. I don't know if I like it tho.....makes for a pretty short area with splines.....a better deal would be to have aftermarket axles made. I haven't attempted installing the 64 center section in the 57 housing but the "big boys" tell me there is a little clearancing to be done on the housing with a die grinder....
Just give it to me and slap a Ford 9inch under there! I'll take that mess off your hands.......AND I WON"T EVEN CHARGE YOU! xxx Brandy
Richmond still makes gears for 57-64 Olds/Pontiac rears. Unfortunately they only offer 4.10, 4.56, & 4.88:1. If you have not noticed any chirping around corners, it is not a spool or welded spiders. It may be a posi or locker for the later rears. John Gevo of Gevos Rears and Gears usually has parts on hand. He is out of eastern NY but I don't have his number at hand. I can get it if needed, just let me know.
I could probably get away with a 4.10 if I had to (it's still a BIG improvement over the 5.13!), so If I can't find anything else I'l go that route... Thanks! Steve
Richmond makes gears as mentioned earlier.I think you'll like 411 ok.With a nice tall tire you'll be turning in the 28-3 k neighborhood at 70.That ain't to bad.A stocko 326 set is kinda lazy out of the gate but man you can roll on the top end.With a baby holley and a 350 sbc and a 4 spd in my old ford,I was gettin22-4 mpg and could run around 135-138 unwound.An old car that can wave bye bye to the guy in the other lane at 100 plus is loads of fun. T.OUT
Yeah, I've got 4.11s in my chevy II with 30" tires and that's about perfect. I only have 28" tires on the '55 right now (L60-15's), so I thought a 3.90 would be ok... Plus, it's got a 500 lb/ft small block in it right now, and when that comes out it's getting a stroked 427T, so it will be able to move the car, regardless of the gear!
Ok guys.... I just tore this apart tonight to check out the leaky axle seal issue. Now I'm confused (more than usual). The center section is dated '57, it has 29 spline axles, and a posi (with a 5.13 gear), BUT the posi is dated from '63!?! Shouldn't a '63 have 31 spline axles? I'll post some pics tomorrow if it will help...
There is a '57 Olds/Poncho rear in my '55... it had the newer Olds pumpkin with the axles cut off... How do you tell the Poncho from the Olds? I think it is a Poncho because the backing plates don't look like any other backing plate I have seen on the other Olds rears I have pulled/seen. ('63 &'61) I bought a 4.88 spool for 35 spline axles... bought new MW axles that look like baseball bats... should be good for what I'm doing. Sam.
Nahhh... this was an old post. I just brought it back to the top with the questions about the axles. If you can cut down 31 spline axles to fit the later posi, how do I have a seemingly later posi that still takes the 29 spline axles?!? You're right though Sam... even these stock 29 spline axles are HUGE! After having this apart and looking at how beefy everything is, I can definitely see where these rears be hard to break!
The gods have smiled on our Pontiacs again: "NOW ON SALE: The fabled 1957-1964 Pontiac rear end ring & pinions. Highest of quality alloy. Made in the U.S.A. Brand new in box. Available in 3.42, 3.64, 3.90, 4.10, 4.30, 4.56, 4.88 ratios. Race proven, super tough. Large 9.3" ring gear. Timken bearing installation kit also available. Call Fabcraft Metalworks for pricing and order today. 1-800-208-8242"
Now if someone would make a detroit locker style posi unit... or at least something as strong... Sam.
The word on the street is that Brad at Fabcraft will be making a locker for the Poncho rear in the near future.
I'v eheard rumors of using a 9 1/4 mopar truck posi in the olds/pont. From what I had heard you just have to elongate the holes in the carrier to match the ring gear. The car with it was about 3 years ago on the R&C Ego Rama. The red 55 or 56 chevy. jerry
Fabcraft's site shows gear sets from 3.42 to 4.88 for $399 and doesn't mention whether they're intended for street or strip. http://www.fabcraftmetalworks.com/index.php?id=10010&CategoryID=6 An alternative is to refer to the article by Tom Grasso that was printed in issue 38 of Gasser Wars magazine, titled "Good News for Old Rear Ends". In his article, Tom shows how to change the bolt pattern in a '57-'64 Olds or Pontiac housing and then install a Ford nine-inch center section. Here's a link to the Gasser Wars magazine site: http://www.gasserwarsgassermagazine.com/ Dave Mann (602) 233-8400 weekdays http://www.roadsters.com/
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