[yak]

looking for advice on my 1970 gto judge. has an e head .060 over 400, approx. 500 horse, and 4 speed m21 and 10 bolt diff with 4.10s. im running 275/60 15 drag radials on 10 inch rims but will be looking to switch to 8 inch rims ( not sure on tire size yet) my posi kicks out in the burnout box and I have traction issues at the starting line caused by worn posi and a poor suspension set-up. only put 10 1/8th mile passes on the car since 1996 but will be racing it quite a bit more now.

im going to start with putting in a spool but wondering if I need to upgrade the axle shafts as well for my application? or will just a spool and new upgraded lug studs be good for now? thanks

[Tim Corcoran]

It's dangerous to run stock axles for drag racing your chances of breaking an axle is good. You can pick up a set of Moser stock replacement steel axles pretty cheap. The factory cast axles are good but for regular drag racing with a sticky tire is not a good idea.

[Dragncar]

Wait a minute. Factory "cast" axles. I would think they are all steel. Anyone know for sure ?

['ol Pinion head]

8.2 Pontiac 10bolt?
if so, time to upgrade to a stronger rearend.

[455firebird1969]

Originally Posted by Tim Corcoran

It's dangerous to run stock axles for drag racing your chances of breaking an axle is good. You can pick up a set of Moser stock replacement steel axles pretty cheap. The factory cast axles are good but for regular drag racing with a sticky tire is not a good idea.

Agree, it's called fatigue cracking. Any new replacement axle will be better than running a 40-45 year old axle with fatigue cracks waiting to let loose.

[yak]

Originally Posted by 'ol Pinion head

8.2 Pontiac 10bolt?
if so, time to upgrade to a stronger rearend.

there was another guy at the track running a gto, 468? stroker 4 gear and still had a 10 bolt in it and he was pulling the wheels at the line. said he's got hundreds of passes on it. a 12 bolt or ford 9 would be nice though but $$$$$.

[yak]

Originally Posted by Dragncar

Wait a minute. Factory "cast" axles. I would think they are all steel. Anyone know for sure ?

I was told ram air gtos came with stronger axle shafts than a regular gto...

[Dragncar]

I am sure they did. But I can not see GM use cast anything for a axle. Cast steel, or even worse cast iron. Just too brittle. Cast steel can take a beating. I am a welder by trade and weld cast steel hog hammers. Even when a big chunk of steel, 30- 40 pounds gets by the metal detector for some reason they are beat up but do not shatter like you might think. Cast iron and they would chunk apart.
Tell you what, when I was a kid my parents 66 Catalina station wagon lost the bearing retainer and the axle started to come out. This while going into a tunnel on the CA Oregon border mind you. The axle came over half way out before mom got the car stopped. We had to walk on the tiny sidewalk on the tunnels edge all the way out. Kind of scary, I was 10. But my dad was a mechanic and the axle was still good. If it was cast anything it would have been ruined. It has to be forged steel of some kind.
I think if Detroit used cast axles it would be death, mayhem and lawsuits.

[Half-Inch Stud]

Doing the Cliff Claven here;

BOP 10-Bolt axles were cast steel (Armasteel?)

alleged "Hot-Forged axles" were put in 1969-1970 3.90 POSI 10-Bolts with "N"case casting, but my 2nd hand3.90 reared 70 GTO showed cast axles.

All chevy 12-Bolts had forged axles yet also had the AXLE serve as the cost-reduced bearing's inner race: just grand for starting crack-propagations

[Dragncar]

Thank s Cliff..... I mean HIS. That is exactly what I was looking for. Guess I wont be letting my wife drag race her 79 TA whenever it gets done unless there is a upgrade.

[yak]

heres my car at the track doing an 1/8 mile run.

https://www.youtube.com/watch?v=1g8JjJgsvlQ

suspension isn't set up for a good launch at this point plus the posi let go. right now planning on-
-remove front swaybar
-install comp engineering shocks on front set at 90/10
-26x10x15 slicks
-30 spline spool and new axle shafts
-remove coil over shocks and install c e shocks
-edelbrock antihop bars have been installed previously

any other tips or tricks????

[JSPONT]

With a stick shift car, buy good axels. What do you have for rear suspension? With the stick, a set of tubular upper and lower arms and torque braces work well. Here is a great rear sway bar set up. Look at sku 922

http://www.spohn.net/shop/1968-1972-...s-Accessories/

[yak]

Originally Posted by JSPONT

With a stick shift car, buy good axels. What do you have for rear suspension? With the stick, a set of tubular upper and lower arms and torque braces work well. Here is a great rear sway bar set up. Look at sku 922

http://www.spohn.net/shop/1968-1972-...s-Accessories/

my rear suspension is stock plus new bushings in control arms, antihop bars, coil over shocks and moog cargo coils. back in the day with lower hps and big rubber it hooked ok but now all I do is spin out.....

what does that roll bar bolt to at the top, the floor pan??

[JSPONT]

No the frame rails, with a stick shift car, at least box the lower arms. There is a thread on here I posted my UMI brackets. 4 speed cars had them. I'll try and find the link and post it for you.

[JSPONT]

http://forums.maxperformanceinc.com/...d.php?t=769912