a new rearend
 

With help from another question thread I had I've decided to buy a Moser 12 bolt for my 1967 GTO.

So I'm not ready to write a check yet but in preparation I'm going through their order form and need some advice. Per the form they lump our A bodies into the years 1964-1967 & 1968-1972. I've been under the impression that 1964-1965 are shorter than 1966 and on. There is sooo much conflicting information out there I just don't know. I have an 8.2 out of a 1969 Grand Prix under there right now. Per measurements and calculations it appears the 8" Rally I with 5" offset I want to go with will fit fine so maybe it is just a dumb question at this point to just not order for a 1969 but this kind of thing make me kind of second guess things.

Do you have particular experience with this situation and suggestions for a good question or two when talking with Moser?

Thanks

Ask what the flange to flange difference is between the two.

Then get the wider of the two if you want a stock width rear.

Sometimes getting the 1” narrower earlier rear can be an advantage when you’re stuffing in wider tires. If your situation would benefit from tucking the tires in an additional 1/2” on each side then buy the narrower earlier version.

67 GTO/LeMans rears are 54.5 from backing plate to backing plate. I've had 2 of these cars and both of them had 54.5" between the inside of the backing plates. That gives about 60" to 60.5" drum to drum. On a car with perfect wheelhousings, a 275/15 drag radial will just fit, if you lift the rear suspension about 1.5 inches.

More info:

https://forums.maxperformanceinc.com...d.php?t=416764

Just an FYI for you...I have a 69 rear in my 67 and I have 5.5" backspace on the wheels and I'm not sure a 5" backspace would work. 255/45/17 tires 8" rim

I believe that they lump pontiac 64-67 together because that's the way chevelles were configured, same width 64-67. 64-65 Pontiac a-body rear was indeed 1" narrower than 66-67
'

I have a 69 Chevelle 12 bolt under my 67 LeMans. It’s more of a pro touring setup: lowered with SPC springs(~1 inch on the rear), 17x8 Superlites(4.5” BS, 0 offset), 245/45/17 BFG SportComps(25.7 inches tall). It generally works but I do get major rubbing on the outside of the tires if my car has more than 3 people in it.

I would personally recommend the narrower early setup. From what I’ve seen, most 8” wide wheels have around 4.5” backspacing, but if you were gonna go with custom wheels it wouldn’t be an issue either way.

Since I can’t stomach custom wheel prices, and would drastically change the vibe of the car, I’m planning on narrowing my 12 bolt and converting it to bolt in axles. Then I should be able to run 9.5” wide wheels and 275s.

Plenty of 8" regularly stocked wheels with more than 4.5" BS out there without going to custom wheels, if you're not stuck on the Superlites.

Just one example - Boyd Coddington Junkyard Dog's are available in both 4.75" and 5" BS for $261.00 per wheel at Summit:

https://static.summitracing.com/glob...575g_lm_ml.jpg

Other wheels in 17x8 go all the way to 5.5" BS:

5.25" Vision

https://static.summitracing.com/glob...h5761c6_ml.jpg

5.5" AR

https://static.summitracing.com/glob...8956547_ml.jpg

Bottom line, good looking affordable wheels with decent BS are readily available.

Order your new 8” Rally I wheels with the 5” backspace and test fit them on your current stock width rear end.

I’m betting you’ll find that the early narrow rear end with put the wheels where you want them. From my own experience centering an 8” wheel you need 5-1/2” backspace with the wider rear end and 5” backspace with the narrow earlier rear end.

So get your rims first so you can physically check and measure the clearances. Put both bare wheels on and set the car down on wood blocks that fit between the beads of the wheels. Then check everything and make your decision.

My 65 GTO stock width has extra 275-60-15 BFGs on a 81 Trans Am 8" 15" Turbo wheel. 1/2 inch offset. My 0 offset Cragar SS on my 64 Impala will not fit.

I found a early Chevelle 12 bolt that may go in it or sell and and put a Moser that is beefier in it.

Unless your heart is just set on a 12 bolt call Quick Performance and tell them what you are trying to accomplish and get a 9 inch. So much cheaper for better options and yes I have Moser Axles.

Moser also has Strange 60s bolt in.

Couple suggestions when ordering a Moser 12 bolt:

Always get it at least 1/2-3/4" narrower each side than what you need, so if you convert to disc brakes in the rear, it won't push them out and make you buy new wheels.

Have them install the 'hybrid' axle flange, which is a 12 bolt flange that uses the big ford bearing.

Order the axle access holes.

Order a 1350 yoke. (And yes, change your slip yoke too).

Bolt in axles is a no-brainer.

Don't order via the form on the web, call them.

Measure your current rear flange to flange before you call and go from there. Tell them the year you have, ask them what the width is, and if it's not what you have, tell them.

If you can afford the few extra bux for a true trac, get it.

As for the Ford 9" / 12-bolt / S60 debate, in my opinion, there's no reason to do anything other than a 12 bolt unless you have big power and plan to abuse it at the track. If you outfit a street/strip 'performance' 9", it's about the same cost as the moser 12, or close enough not to make cost a factor. Same with the S60.


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I have a 12 bolt in my 65 LeMans that I pulled out of a Chevelle in a wrecking yard back in 1995. I put in a strange spool 3.73 gears and Moser 30 spline axles. I didn't know about the Ford bearing conversion at the time but I wish I did it. I did install C-Clip eliminators on it and have had trouble with them leaking over the years but I figured out how to solve that. I installed a billet rear cover that you can apply torque to cap screws that gives it extra strength. I ran it on the street for many years and it's now a drag only low 10 second car doing 1.4 to 1.5 60 ft times with slicks. Been racing it for many years and did change the oil once and it held up just fine. It's lighter than the Dana 60 and Ford 9. Whatever you get just make sure you specify the width you want, I believe the way they measure them is from inside the backing plates but verify that with who you get it from.

Yes, Moser strongly recommends the bolt in axles, and they make 2 different housing ends that use the big Ford bearing, the 7900, and the 7900FM (Flush Mount). The FMs are for certain type of disc brake setups, but if you just do the regular 7900 and do a 'conversion' brake setup, you're golden. I would suggest speaking to someone about it when one calls them to order.

https://www.moserengineering.com/790...lip-axles.item

FM style:

https://www.moserengineering.com/790...lip-axles.item

They are game changers for sure. Even if you never do any strip whatever, it is still worth spending the $80 bux. Pretty sure they give you a deal on them when you order housing, might be less than $80.

If you can swing the cover girdle I would strongly recommend that.

As I'm sure all know, Moser casts their' own center housing section and are much stronger than stock.

You never know if a used housing is 'true', and not many have jigs to determine squareness. I know many will say 'aw you don't need no stinkin jig' but to have the piece of mind is priceless. I struggled with an out-of-square housing for a long time, then finally did a Moser, and boom, done. (I would eat axle and carrier bearings)

Pretty sure Moser housings come with billet caps, at least all the ones I have did.

EDIT: Their' axle tubes are of thicker material too, and they brace the brackets.



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This is the way.

Have you removed your center section? Has it ever been removed by others?

This is the way

Strange 9" Ford Center Section. (Thanks Larry Kaufmann) Moser Rear Housing.
Rear Explorer rear did brakes. 12" front brakes. No issues in 20+ years.

Tom V.

I'm not totally clear on what you're asking, but I haven't removed the center section of my Quick Performance 9" since I assembled it a few years ago.

With a new fabricated housing, 1/4" wall axle tubes, billet pinion and yoke, Yukon Pro N case, TrueTrac LSD, and disc brakes, it was an excellent buy for $2500. It'll hold 700hp and changing gear ratios is simple.

Another happy 9" Ford Guy with no issues.

Tom V.

No question, just wordplay on the Mandelorian code and "this is the way".

I agree that Ford 9" is the way to go if there is any chance of changing gear ratios in the future. The gear ratios, parts support and robustness is there. I've got 3.25s and 3.89 center sections for mine. Just make sure you spec them all with the same axle splines and yoke as what the car is set up for. Right now Quick Performance has the best deal on 3rd members.