stock elimator rear axle?
 

why is it that nhra ruled that a car [any car] can update to a different year rear axle, but it has to be by that mfgr.?
i have nothing against a 12 bolt, but i do not see a drop out center '56 chevy rear being any where near a 12 bolt chevy. whereas a 9" is almost exactly the same axle.
what if you had a '50 olds, your choice would be to a clunky, heavy, out dated and weak '57 axle or a B.O.P. rear from the 60's. no choice.

thoughts

thanks rod in AZ

Re: stock elimator rear axle?
 

Youse picks the combination youse follow the rules.If the 50 Olds was put back in the guide you could probably get away with the early Olds,if you can get the gears you want.Otherwise you put a 12 bolt in.But since the only early cars reinstated are the 55 Chevies you have the same choice.I think the strength of the 12 bolt speaks for itself.How many are under GM stockers?

Re: stock elimator rear axle?
 

would it be the same as "corporate" rear?
i can run a 8 3/4" mopar rear (and am) in my amc,wouldn't the same apply to the olds?
i'd think a 12 bolt would be legal but i'm not the guy making up the rules..

Re: stock elimator rear axle?
 

Tom is right. The key word in the rules is "corporate". If you had a 56 Chevey stocker, any GM passenger car rear would be OK. Most would use a 12 bolt or an 8.5, strength and gear selection being the criteria for judgement. Your 57 Olds analogy is a little off base. Those rears are very strong but the gear selection nowdays is poor and they are heavy. I agree that in these days of purpose built stockers, the rear end rule is one of our "stupid" rules but the present rule beats the original rule hands down. Back in the day, the Ford guys got to use the 9in, the Mopars got Dana's and 8 3/4's and the Chevy guys got.....you guessed it, the Chevy dropout. As sticks were the transmission of choice, you can imagine the result. TT

Re: stock elimator rear axle?
 

In the second half of the 60s, Olds and Pontiac bought Ford top loader "Dearborn" three speeds. Hmmm, that makes Ford a drivetrain vendor to GM. Now can Olds use the 9" Ford rear?

Re: stock elimator rear axle?
 

I think that it has been worded like this to allow the new and old cars both to be able to use a rear end housing manufactued by its corporate company, the corvettes have independent rear axles as do the new challengers and camaros maybe even the production mustangs. It allows the racer to put in the strongest its manufacturer has to offer and the safest for the racer, competitors and spectators.

Re: stock elimator rear axle?
 

Today, a rear is built with aftermarket "everything" sometimes even the housing like on 12 bolts and Danas. The cost is very similar for whatever you choose to build. If safety is the issue, why does NHRA care what diff you use? If a Vette can convert to a solid axle, the horse is out of the barn.

Re: stock elimator rear axle?
 

A lot of formerly fast D/S cars sure let their voices heard when I had them all covered and in the process had a Dana 60 under my D/S '70 AMX! Apparently the fact that AMC was bought by Chrysler in 1987 meant nothing and it was a corporate merger. Corporate rear ends have always been allowed.
That means corporate, not anything else so no 9" Fords under an old Pontiac.
As mentioned earlier, that's just part of the game and if your choice of ride is limited in this department, look at something else! Or another alternative is to make what your offered work. Anything can be made to work with cubic dollars! :D

Re: stock elimator rear axle?
 

Run to Rund;
The Corvette (and any other swing axle car) is allowed by NHRA to use a solid rear as a safety item. If you had ever seen what a broken halfshaft can do you would most likely understand. The rules for replacement of the swing axle (especially for Corvette) are hardly a carte blanche suspension bonus. The adaptation for the solid housing must utilize all of the OE attachment points and trailing arm configuration; shock mounts included and then there is that pesky transverse leaf spring (another bonus). I have two of these cars; a 71 (C3) and a 96 (C4) with solid rears. They are not even similar as the rear suspension is very different in O.E. design. Both were a challenge to sort out but thanks to Alf Wiebe and a fairly serious testing program they turned out to be pretty good little race cars. Are they better than a Camaro? Maybe in theory but in the real world?.......I doubt it. By the way, these cars work great with a swing axle. TT

Re: stock elimator rear axle?
 

Besides being a whole lotta work and R & D, I'm sure it wasn't cheap either.
And in the end, it's still corporate.

Re: stock elimator rear axle?
 

Tom, I have no problem with NHRA allowing the removal of the swing axle grenade. I am just trying to follow the logic. If safety is important, why force some to use weaker parts which cost the same or more? Fortunately for AMC racers, Chrysler bought AMC and NHRA lets them run better diffs like the Dana. GM racers have to run the 12 bolt which takes a lot work to make it live in fast classes, and I suspect most of them are all aftermarket parts, not even the housing being from GM. The benefit seems to be lower HP drag than the 9". My point of logic is that there seems to be no safety or cost related reason to NHRA's decision. Neither are they preserving "originality" since everything is aftermarket anyway. Among the Ford guys, they have to spend the same money for 28 spline pinion pro gears, instead of getting the stronger 35 spline pinions. It would seem to make better sense to "level the playing field" and let any car rearend be used, period.

Re: stock elimator rear axle?
 

Run to Rund.
If you insist on using the term "logic" in reference to most NHRA rules, you risk the possibility of sounding profoundly oxymoronic. If you refer to my first post on this thread and find the word "stupid", you will discover that you and I totally agree on this subject. Sorry about the sermon on solid axle conversions but I tend to be a little sensitive on the subject after enduring the anti corvette faction for many years. TT

Re: stock elimator rear axle?
 

lol, I forgot who we are dealiing with here.

Re: stock elimator rear axle?
 

Joe, It looks nice under there but bite the bullit, sell it put the 12 bolt in it and race it in class.--------Danny

Re: stock elimator rear axle?
 

I'm at a loss to think of any make vehicle that NHRA does not allow a structurally sound rear end. All Fords get to use the 9", All GM's get to use a 12 bolt and all Chrysler products get to use the Dana 60. And the swing axle issue has been resolved with either structurally superior parts or a straight axle conversion. The after market makes every part needed for these and if you want to use an inferior, yet brand specific, rear end (like a 8" Ford instead of a 9" Ford) for a possible performance advantage (less drag I suppose), the choice is available. But if it blows up it's not NHRA's fault, it's the racer who chose that route.
I get soooo tired of the "safety" bait when used by a racer that can't afford a part or wants the simple way around the rule book. Real safety is not driving a vehicle in a timed acceleration speed contest!

Re: stock elimator rear axle?
 

Hey Danny, is that you whom I mentioned in the article? Remember telling me that the shroud would be "expensive?" Do you still have your black 66?

Re: stock elimator rear axle?
 

Tom, Yes I still have my Black 66 . Haven't driven it sinse I hurt it in 68. Nice article, great shot of you and Sam lined up. I'm as old as the year of my car now so I might be a little fuzzy on things from almost 40 years ago. --------Danny

Re: stock elimator rear axle?
 

Danny- I presume you're the same Danny Lattimore formerly from Virginia that's been driving Craig Couris' Olds recently? If so, could you please send me a PM.

Re: stock elimator rear axle?
 

Danny, are you in pt. st. lucie now?

Re: stock elimator rear axle?
 

Jim kaekel----Yes that's me, How you been, What's up ----Jim woods----Only when I can get away from here---about 4 weeks a year right now.

Re: stock elimator rear axle?
 

Danny: Could you e-mail me at jkaekel@laneautomotive.com. I've got a couple of questions for you. Thank you.

Re: stock elimator rear axle?
 

Jim, Please take this the right way. If your questions are about Craigs Cutlass and not about women or fishing, I'm going to have to ask you to contact Craig direct. He's spent a fortune on an intense 3 years of r&d and it just wouldn't be ethical for me to discuss his car without his knowledge. I'm sure you will understand my position.--------Danny

Re: stock elimator rear axle?
 

Danny I hope to get a chance to meet you. I have owned the Tanker in the past and currently own the 455 Black K/SA with the title still in your name LOL :) anyhow hope to run into you at the races this year. Later Daran

Re: stock elimator rear axle?
 

Daran, You better go put that title in your name or I'm going to file for a lost title and you will meet me sooner than you think. Hey just teasin, If that were the case Kenny Shawver could come over anytime and take back my 71 stocker. :-) -----Danny

Re: stock elimator rear axle?
 

back to my original posted question. in my old AHRA stock class car ['56 Chevy Nomad] i have a 9" ford which was legal under the then AHRA rules. i have about $1500 dollars in that unit. now in order to run under the new NHRA stock class i would have to run a 12 Bolt, as there is nothing else worth consideration. it is very possible to run a 265 with a stock 12 bolt housing with welded tubes [no need for a fabed up unit] and then lots of $$$$$ to duplicate exactly what i have now. and again the 9" looks just like a '56 drop out, whereas a 12 bolt looks nothing like the original. NHRA is so picky about a piston # and then lets a racer place something completely different for a rear axle. i don't get it. and i am ticked.
suppose for a minute, since the AMC subject has been brought up, that racer A spent big bucks to put a dana 60 in his AMC and then NHRA said only AMC rears would be legal. now you have to duplicate another rear to get exactly where you just were. and have a rear with almost no resale value [being car specific].
it is entirely possible to make a '56 car axle housing into a race unit. 30 spline MoPar side gears in the posi and big ford bearing ends with big race axles and some type adaption for brakes and several mods to the case. [i still have my Jere Stahl 5.57 with all that done]. in the end i would still have a smaller dia. ring gear, and lots of $$$$. what's the purpose
now let me get on my soap box [wasn't i just there?]
the '57-64 Olds/Pont. rear was just BIG, not strong. in a popular hot rodding survey, in a list of the top 10 rears, usable for drag racing, that rear came in 7th.
the 9" fords uses about 4 more horsepower than a 12 bolt. using conventional gear lube. maybe when looking for that last hundredth, that might make a difference. however you can loose more than than by not having the lube up to operating temp.

all in all, if NHRA says rears axle updates in mfgr' only, then so be it. maybe some guys will build new '56 chevy stockers and not have to worry about my problem. i do not have to run under their rules. that is my choice. in the end i wonder who really looses. NHRA has crapped on door slammers for way to long and are now crying for help with car entry. maybe they will change with enough protest. i will start monday.

i do appreciate all the input.
rod in AZ

Re: stock elimator rear axle?
 

I would like to add to this thread an experience I had. I am building a 60 Corvette and was looking to go (Stock) racing. When it came to the rear, I wanted to use a 12 bolt for different reasons. Everyone (friends, racers, NHRA tech personel) said, no problem go ahead an use it. Everyone except Wesley Roberson NHRA Div 4 tech. The rule book said the replacement rear must be the same "type" from the same corporate family. The word "type" meant spicer (rear loading) or 3rd member (front loading). So you could not use a 12 bolt in the 53-62 Corvette (Wesley). After doing some investigation of my own, I found many violations to the rule book on rears. Including a few direct violations setting on world records, and not just Chevys. I gave no information on the cars and/or names. I did go a few rounds with Mr Bruce Bachelder at NHRA. In the end the 2010 rule book was ammended and the word "type" is no longer there. Now it's just a rear from the same family. So you guys with the 55's can go ahead with the 12 bolt "and be legal" now. After all that mess, could'nt get a 9 inch tire on the Corvette anyway.....so I went to a 10.5 and had to move it to S/S....there were several other issues on the car that made it more favorable to go S/S.

Wade Mahaffey