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3.93 to 3.36

4K views 16 replies 6 participants last post by  70gto 
#1 ·
Hi guys!
So, I took my car to get the rear end checked out. He wanted to charge me to take off the housing to check the gears, but I just had him check to see if it was an open carrier. I hope that's the right terminology...anyways, it seems to be a limited slip, so can I go from 3.93 to 3.36 without changing anything but the ring and pinion? I can't seem to find 3.36 anywhere even at Randy's Ring and Pinion. Any suggestions?
Linda
PS. Also, the guy said that Randy's Ring and Pinion can get 3.55, but that's still a little too stiff for me. He said that they can modify a Chevy gear, but you would have to change out the yolk, yadda yadda yadda. It would be three times as much.
 
#2 ·
Hi Linda. You're doing the right thing. A 3.36 gear is perfect for your '67. It was the standard ratio for automatic trans GTO's in '67. Good power, good acceleration, decent fuel mileage/cruising at highway speeds. A 3.36 is as "long'legged" as you can go with your 4-series carrier. I know. I did the same change. I was able to locate a set of original, used gears for mine. The ring and pinion on these cars almost never wore out, so you should be able to find a matched set of good used gears. I would NOT go 3.55 with your car......with the automatic, you'll be sucking fuel and revving high at freeway speeds. Good luck, and if I come across any 3.36 gearsets, I'll let you know asap.
Jeff
 
#7 ·
Hi Linda. 450 probably is accurate. It may be cheaper to find another entire rear end assembly and swap it in. You may be able to find a '66-'72 ten bolt safety-trac (posi) for around 400 dollars in a 3.36 ratio. A very easy, low tech job. You could ebay your 3.93 posi and more than make out. (steeper geared rear ends bring more $$). Sandu: 3.23 gears WILL NOT work in Linda's 4-series carrier. The lowest numerical ratio she can use is a 3.36 if she just changes the ring and pinion.
Jeff
 
#8 ·
Cost

I don't know about where you guys live, but they wanted $450 in labor + parts! I don't know why, maybe they're trying to take advantage of Blondie67 because I am blond? :) Some places even quoted me as high as 1600 to do the job. I'm about ready to call this old guy that has had a shop for years and have him do it. He probably knows old cars inside and out and has been doing them for 60 years. He'd probably only charge me $100....
Linda
 
#10 ·
#12 · (Edited)
Finally!

Okay, so I got the part numbers from the guy I bought the GTO from. They are Jeg numbers and it turned out to be 10 bolt limited slip 3.55 gears 28 spline 8.2, whatever that part means.....but I guess I'll figure that out. Apparently with this carrier, you can go to 3.36.
So, if anyone sees a used 3.36 set up, please let me know.
Linda

Called Randy's Ring and Pinion, apparently the GM model won't fit, but they have it listed. I'd need to do a conversion. A lot more money.....maybe I'll just leave the 3.55 for now.
 
#13 ·
Linda: Check out Richmond Gear's catalog. They offer a 3.36 ring and pinion setup for the 10 bolt. Also, you could keep the 3.55's and bolt in a 700R4 overdrive trans.....but that's a whole 'nother ball game. If I were in your place, I'd enjoy the car while hunting down the 3.36 gears, or a complete, used, 3.23 or 3.36 rear end. No rush......You'll get it done.
Jeff
 
#15 ·
Depending on the size of the shop they are going to mark up the parts. Most ASE shops are charging $80 to $110 and hour. The set up is critical , so after inking the gears and seting up back lash it could take 2 to 5 hours . And some shops will charge list on parts not what Randys sells them for. ie list on a 3.55 is $511.50, for ring and pinion. List on a set up kit is $113 to $ 257 for a eaton rear. You have to remember shops have "overhead" that is the cost of insurance, marketing, training, equipment, ...so dont assume they are taking advantage of you, look around is it a big shop with lots of employees or is a 2 bay gas station that has grease for wall coverings.
 
#16 ·
Overhead

Trust me....I know about overhead (I operate two businesses myself). But I also know I've been told stories and have had attempts to snow me. Luckily I know a little about cars and I've called them on it. I'm learning a lot about rear ends now, so at least I am a little bit informed when I go to a shop. The ranges I've found are $450 for labor plus parts to $1600.00 for the whole job. I might just visit one of those "Joe's Garage" shops.

Linda
 
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