Anyone looking for a rearend with a taller ratio????

[Sumner]

    If you are looking for taller gears (lower numerical gear ratio) for a land speed car there are a few choices. With a Ford 9 inch 2.47 is as low as you will be able to go. There has been talk of a few lower ratios being made, but I've never found them after extensive searches and phone calls.

    In the GM line 2.41 is it for most of the popular rearends that can handle more HP. The 10 bolt 7.5 rear though does have 2.28 and 2.14 gears and these rearends have been used with success. One example is Sparky used one in his low 900 HP na BBC to set records in the high 200's and low 300's. The car weighed a little over 3000 lb.. You can also find Torsen type posi's from late 90's Camaro's for these rearends at a resonable price new on ebay. The Torsen has a positive aspect to it in that it can transfer power from the wheel without traction to the one with traction if different ratios. I'm using one of these rearends in the lakester with the Torsen and 2.14 gears but doubt this car will ever have more than 900 HP if that.

    Hooley's Stude has had a 2.47 nine inch Ford rearend and runs a G-Force 101A transmission that lets him run an overdrive 3rd gear as 4th gear with the old 4th (1 to 1) now 3rd. To keep the jump between 3rd and 4th in the 15% or less range it would be nice to put in a rear with the 2.14 or 2.28 ratio. Problem is the car is heavy, over 5000 lb., and with the twin turbos on the 572 BBC now has the potential of 1500+ HP levels. It is doubtful if the GM 7.5 is up to the HP and the weight.

    One option we have been pursuing is a kind of odd-ball GM rearend that was made for the heavier GM cars in the 70's. It is the GM 8.75 that is in a 10 bolt housing but there again not the housing you normally see as a 10 bolt.



    It looks like the one in the picture above with the inward scallops on the sides of the cover by the axle tubes. It came with 28 and 31 spline axles and the ring gear is held on with 12 bolts vs. the more normal 10 bolts for ring gears in other 10 Bolt rearends. It has a 1 1/4 inch pinion nut with 3 inch axle tubes.

    The lowest ratio for this rearend is a 2.28 (no 2.14) but the good news is that it is a very strong rearend compared to the 7.5 10 bolt. The ring and pinion gears and the pinion shaft are all much larger than the 7.5 inch rearend. It looks like a very good choice for the Studebaker and probably a number of other cars that run over 275 mph but for a couple facts about it.

    So what is the 'bad'? The rearend was never popular with the aftermarket, probably mainly because most are looking for a rearend with much lower gears for the dragstrip just the opposite the gearing requirements for our needs and there were other popular rearends, such as the 9 inch Ford, with those ratios. You can find some with a posi, but Eaton only made the posi for GM (not as an aftermarket) and talking to Eaton on the phone they no longer support the rearend so posi parts are going to have to probably be found used or NOS. Also I can not find anyone who made a spool for the rearend so unless you want to run it open or with a posi that might not be serviceable you are out of luck.

    I've made a couple calls to see if anyone is interested in making a spool for the rearend. Mark Williams said they might be interested and said they could make axles and I have a lead with another manufacture that I haven't heard back from that might be able to make a spool. Ford axle ends can be welded on to get around the C-clip issue.

    So, the reason I've posted all of this is to see if anyone else might be interested in this rearend and in a spool for one. I'm figuring that if someone was to make more than one spool the price would come down and they might be more interested in taking this on.

    If you are interested please post here on landracing.com or send me a PM or if you are reading this on my site send me an email at:

    ( contact20 (at) purplesagetradingpost (dot) com

    Also if anyone has any other info on this rearend I'd like to hear about it.

    Below are pictures comparing 7.5 ring and pinion gears vs. the 8.75 and more info about the 8.75 can be found here.....

http://www.crankshaftcoalition.com/wiki/Rearend_identification#10_bolt

   As you can see there were a number of cars with these rearends so finding one is not that hard and I've seen posts on the internet where guys with 2.28 gears are trying to find lower gears to improve performance so the 2.28 gear sets are out there,

    Sum

NOTE:  You might want to go to my site here....

http://purplesagetradingpost.com/sumner/bvillecar-4/gm%207%201-2%20vs%20gm%208%203-4.html

... and bookmark this page just in case this might be of interest to you in the future.

=================== More Pictures ( click on the link for larger versions)===============



http://purplesagetradingpost.com/sumner/bvillecar-4/7%201-2%20vs%208%203-4%20rearend-1.jpg



http://purplesagetradingpost.com/sumner/bvillecar-4/7%201-2%20vs%208%203-4%20rearend-2.jpg



http://purplesagetradingpost.com/sumner/bvillecar-4/7%201-2%20vs%208%203-4%20rearend-3.jpg



http://purplesagetradingpost.com/sumner/bvillecar-4/7%201-2%20vs%208%203-4%20rearend-4.jpg



http://purplesagetradingpost.com/sumner/bvillecar-4/7%201-2%20vs%208%203-4%20rearend-5.jpg

[manta22]

Good info, Sum-- thanks.

Regards, Neil  Tucson, AZ

[SPARKY]

Summ I am  sure  it is a 2.14 ratio not a 2.19

[Sumner]

Summ I am  sure  it is a 2.14 ratio not a 2.19

You are right.  I had 2.14 on the picture and then screwed up with the 2.19 in the text and then screwed up and changed the picture to 2.19. 

Well I went and un-screwed up all of that and hopefully changed it all to the correct 2.14.  Does that make sense 

Sum

[Kool Performance]

If anyone is interested I have already made a spool for 1 of these, as well as a 2 series 12 bolt Car. The splines are being broached this Week.  I used 4340 Prehard.  These were pretty common in Cadillac's. Just beware there is an early and late version.  I can also get used gears rem polished.  Give me a call to discuss details Steve 812-305-0710

[Sumner]

... Just beware there is an early and late version.  I can also get used gears rem polished.  Give me a call to discuss details Steve 812-305-0710

Can you elaborate on the 2 versions and which we should be looking for and I'll be giving you a call tomorrow (01-08-14) and thanks,

Sum

[Dynoroom]

Sum, seemed like a good place to mention this;

10 bolt GM 2.14:1 rear end is for sale. Complete as is with Mark Williams axles & Wilwood disc brakes. Ran over 285 MPH in a lakester.

PM if interested

[toclub]

GM also made a 2.29 ratio in the very strong 12 bolt rearends. They are hard to find but they are out there.

[SPARKY]

I looked for 5 years in 7 states. The only one I ever found were the ones in CA that some one had a few sets made. They  wanted $5000. per set if I remember correctly---From the factory they came 1 year in a Chevy Station wagon with at 396 with 2 barrel carb ---again if my memory serves me 

[Ron Gibson]

IIRC, I think the 2.29's were also available in mid to late 70 chevy, full size, highway patrol and some police spec cars.
Al's Weismann transaxle was based on the 12 bolt R&P. He ran them, the 2.29's, until he came up with a set of, I think, 2.14's that Lingenfelter (sp) had special made for the 12 bolt. Talk about hens teeth. Made out of pure unobtanium.

Ron

[desotoman]

Sum,

Not trying to derail your thead, but has anyone ever thought about having a lower numerical gear for the 9" Ford made? Or is a 2.47 the lowest numerical that can be made?

Tom G.

[Bob Drury]

  MacDonald and Pitts have two sets of the Lingenfelter gears, broke both pinion shafts a couple of years back and machined them out to accept new shafts and so far so good with the patch.  They are in fact made of Unobtanium.............. that's what going out the back door at 311 in a Firebird with a flat torque line will do to you.........

[Bob Drury]

  The Ford 8.8 (Mustang/Explorer) might also be looked at.  Some Rangers had a 2.47 8.8 gear, and the  Explorers and GT Mustangs usually have a factory posi, and the 1995 and up Explorers have 31 spline axles.  Both have disc brakes, and if you use two short Explorer axles, it ends up about 57" flange to flange.  Bob

[Dynoroom]

It would be interesting to know where/who the 25 sets of 2.14:1 (Some say 2.13:1) are to day....

Al Teague 'liner (2)

Mindinberg's vette had a set

Lindsey & Leggett firebird?

MacDonald & Pitts (2)

Jonn Rains firebird?

Kugel & LeFevers firebird

Eakers & Staggermeyer (Linginfelter) (2 or 3)?

Others???

[Sumner]

Sum,

Not trying to derail your thead, but has anyone ever thought about having a lower numerical gear for the 9" Ford made? Or is a 2.47 the lowest numerical that can be made?

Tom G.

I guess someone somewhere made taller gears for the Ford 9 inch but I could never find any for sale.  I heard they had some for NASCAR at one time but no idea on the ratio and there again I did a lot of calling and never found any.  One guy was advertising them 4-5 years back but when I called he said the ratio in the add was a mistake.

I have a feeling having them made would require a number of sets and be quite expensive.  I'd think having spools made for this GM 8 3/4 in some kind of quantity would be a lot less expensive.  I talked to Steve today and the one he has made is setup for 35 spline axles.  So with those axles and ford tubes of the proper length and the spool you would be ready to go.

Bob I can't see the advantage of the smaller Ford since the 2.47 gears are available for the 9 inch (what we have been using).

So far I guess no one wants to add their name to the list of "I'd like a spool maybe" so I guess a quantity deal isn't going to happen.  Possibly since Steve has a prototype he would be willing to either make more or for a development fee let some manufacture takes his and duplicate it?  He told me that he would work with us, but not sure if he really wants to go into production or not?  Steve??

Sum