Chevelle Tech - View Profile: big gear head

big gear head big gear head is offline

Senior Tech Team

  Visitor Messages

Showing Visitor Messages 1 to 10 of 21
  1. SupraStore
    Jul 22nd, 18 3:13 AM - permalink

    You don't know me from Adam, but I'm starting with you as someone said talk to Freddie at the Chevelle forum. I have a 71' El Camino that were doing a motor/trans swap on. Test fitting now. I need to think about the rear-end solution. It's a 10 bolt rear now and and the car will make about 750hp at the wheels from a Toyota 2JZ motor single turbo and a 6 speed manual box. It's just a fast street car, no hard launches, but it needs to hold the power. Torque around 550

    I'm looking for a turnkey rear-end (posi) solution with axles, mounts for the 71, and set-up for Wilwood brakes. I can buy direct from Wilwood with a deep discount, but if it makes sense to do everything I will through one person. I'm naturally thinking Ford 9" but not married to it.

    Serious buyer and doing the legwork now, so our guys don't have to re-invent the wheel when it's time to address the rear end. I'd like your opinion and cost ideas.

    Gilbert, AZ
  2. TimP
    Jul 15th, 17 7:08 AM - permalink
    I was lucky enough to find a very clean, complete 12 bolt locally for $800 The only problem was it had a set of 4.88 gears in it with a spacer for the 3 series carrier. I'm building a cruiser so I picked up a set of 3.42 gears and have a local guy setting up the gear set. Hopefully it will be done today.

    I'll save the old 12 bolt housing for a spare or trading material.

  3. TimP
    Jun 9th, 17 11:46 AM - permalink
    Part 2
    Is the housing worth saving? Do I need to get in there with a cutting torch to remove shaft to access the C clips to pull the axles in order to remove the carrier? If I do that can you give me an idea on cost to buy a new carrier, bearings and ring & pinion. I don't really want to set up the gears myself, having never done that. I'm in the Chicago area and suppose I could find a shop to do the work locally. You are 405 miles from me so it would be possible to toss the whole thing in my other car and drive it down to you if needed.

    The El Co is just a street cruiser, small block & automatic, so no super HD rear end in needed.

    So..... Try to save it or scrap it and hope for a good used one?


    Thanks, Tim
    708-927-5223 if you wish to call......thanks again.
  4. TimP
    Jun 9th, 17 11:43 AM - permalink
    Tom, I've been reading a lot of 12 bolt threads and you seem to be the man with the answers. I need some advise.

    I've got a 71/72 Eaton 2.73 rear end in my 68 El Camino. The only reason I opened it up was to replace a bad axle seal. I was a FE/ brake mechanic for 30+ years starting in 1970, so I'm familiar with the problem I've run into, but never quite this bad.

    The pin holding in the spider gear shaft was broken. With much effort I was able to retrieve the piece and the hole for the bolt is clear to the other side of the carrier, but the shaft seems to be galled inside one of the spider gears. I can move it in and out about 1/4 inch but that's it. An air chisel refuses to push the pin out further. When the pin is centered I can move it with finger pressure, but just that 1/4 inch or so. I can see one of the spider gears move up & down with the pin near the end of the play. A assume the pin dug some grooves inside the gear, stopping the removal of the pin.

    Part 1
  5. charbilly2001
    Jan 18th, 16 9:21 PM - permalink
    I put the postal money order in the mail today. No pickup till tomorrow however.

  6. charbilly2001
    Feb 6th, 15 12:16 PM - permalink

    Friend of mine has a beautiful 1967 442 convertible with a 3.08 gearset. He wants me to install a brand new 3.55 GM factory gearset. Any conflict there with the housing or carrier or is it a straight forward change? The kit he has, which is still in the original GM box has everything except the crush spacer.


  7. 70CHEVELLE396
    Jun 29th, 14 8:28 PM - permalink
    Hi, I have seen you mentioned often on the site whenever rear differential questions are asked. If you don't mind I'd like to let you what I have and see if you have any suggestions. I bought a new moser 12 bolt housing (before I heard you were a dealer) with bolt in 33 spline axles. My next purchase is a diff. I am pretty much decided on an eaton clutch posi. I see that moser offers a 33 spline eaton, and I have also seen what Tom's differentials has to offer. As much as I like his tuned and polished units they aren't cheap. The moser setup is about half the cost. I'm wondering what you may have to offer and or any suggestions. I tend to be drawn to the higher end quality products, even though my application doesn't always demand it. Also anytime I can get something that's made in the USA it goes a long way with me. I have 70 chevelle 396 street car, that may see a few trips down the strip. Thanks for any info and suggestions.

  8. Dble07
    Jun 4th, 13 12:30 PM - permalink
    So if my Yukon had green springs does that mean they are 200#? Is there a specific reading that an individual spring would show at installed height(like you would do to check valve springs)? I called Yukon and they said they don't normally install green springs in their units but they verified(from casting marks) that this unit was one of theirs. Would the 400s be better in a street/strip big block chevelle or can I get by with the 200s?
    My #(618)530-1686 if that would be easier. Thank you for your assistance sir.
  9. Dble07
    May 30th, 13 10:39 PM - permalink
    Hi Freddie. From what I've been reading you're the man on rear ends. I'm in the process of rebuilding the 12 bolt. The posi carrier was pretty tore up so I found one that a buddy had but had never used. The unit i believe is a yukon and has green springs(#200) but my old eaton weren't painted so I'm not sure what pressure they are. I want to make sure the unit has #400 springs in it before in gets put back together. Is there a way to test the old springs to verify what pressure they are?
    Thanks, Nick
  10. Restore66
    Mar 28th, 13 11:31 AM - permalink
    I am debating to put Posi and 3.73 gears on the rear end. Is 3.73 gears the correct ones to use? And should i put 3.73 gears and not make it Posi? Any information would help.
    350 motor, 300 HP. 700R trans, 17 or 18 inch wheels. Not looking to race, just cruising and once in a while step on the gas at red lights, etc. Thanks for any help.

  About Me


Total Posts
Visitor Messages
General Information
  • Last Activity: Today 6:06 PM
  • Join Date: Feb 19th, 00
  • Referrals: 1


Showing Friends 1 to 5 of 5


No results to display...


May 16th, 19
3:35 PM - big gear head quoted nashville beth in post Re: 12 bolt from hades
The question I am struggling with i...
May 7th, 19
8:43 PM - JF74chevelle quoted big gear head in post Is this too much free play
Nope. Nothing wrong with that. Ok...
May 5th, 19
5:16 AM - BillyGman quoted big gear head in post Re: 12 bolt trutrak power rating.
You might also look at a Strange S...
May 4th, 19
6:52 PM - 1966_L78 quoted big gear head in post Re: Muncie for a novice
The M20 is the best street Muncie ...
9:40 AM - Rich-L79 quoted big gear head in post Re: Muncie for a novice
You have to be careful about the u...
9:38 AM - David Bates quoted big gear head in post Re: Muncie for a novice
I built a M23Z for my car and it's...
Apr 15th, 19
12:58 PM - SSJohn quoted big gear head in post Re: Moser 12 bolt - order it shortened or no?
All Chevy car rear ends have the p...
12:18 PM - zookpr quoted big gear head in post Re: Moser 12 bolt - order it shortened or no?
All Chevy car rear ends have the p...
Apr 11th, 19
8:05 PM - big gear head quoted nashville beth in post Re: 12 Bolt Upgrade
What do you think of the S60? It s...
7:46 PM - nashville beth quoted big gear head in post Re: 12 Bolt Upgrade
With the value of a '67 12 bolt an...
6:50 PM - big gear head quoted nashville beth in post Re: 12 Bolt Upgrade
Jackie, That is exactly what I w...
12:09 PM - MarkP quoted big gear head in post Re: Clutch recommendation please BBC, 600 hp
I'm using the RXT in my 427 Camaro...
Apr 8th, 19
9:04 AM - David Bates quoted big gear head in post Re: Chevy 8.2 posi questions
Randy's world wide, DTS, and Tom's...
Apr 2nd, 19
2:00 PM - DZAUTO quoted big gear head in post Re: 73-77 Chevelle 10 bolt
Yes, the eyes on top of the housin...
Mar 31st, 19
5:51 PM - Rich-L79 quoted big gear head in post Re: Help me ID 4-speed and diff, '65 El Camino
The Muncie transmission has an all...
Mar 12th, 19
7:50 PM - langss quoted big gear head in post Re: Is it worth it.
It will need machine work after it...
10:48 AM - DZAUTO quoted big gear head in post Re: Is it worth it.
...rrectly. Freddie (Big Gear Head) is right. It will t...
Feb 26th, 19
7:30 AM - Hotwire quoted big gear head in post Re: 9" ?
Except for the 9 bolt Borg Warner ...
Feb 17th, 19
10:51 PM - boyd66k20 quoted big gear head in post Re: 1971 chevelle differential cover 12 bolt
Too much is too much. The additive...
10:27 AM - Rickles quoted big gear head in post Re: 1971 chevelle differential cover 12 bolt
You probably will need the GM oil ...
For the best viewing experience please update your browser to Google Chrome