[455guy]

What parts go first? Gears then ring and pinion?

[455guy]

What parts go first? Gears then ring and pinion?

[bmpmdf]

Spiders thru rear cover, punched hole in gas tank. Bad night street racing ! LOST HALF A TANK OF THE GOOD FUEL !!! UGH !!

[455guy]

Ahh, so I need a stonger rear end cover? Got ya )!!

[455guy]

What engine,car,trans,axel ratio and weight were involved in the ker-splosion??

[455guy]

Does anyone make stronger spider gears???

[Fast 82]

I suggest you change to a 8.5 10 bolt from the Grand Nationals it will last behind a 455 the 7.5 will not last it will be just throwing money away "my oppinion". I have a 82 Grand Prix with a 455 and I switched to a 9" Ford from Moser with 31 spline axles. No Problems! The other thing with the 7.5 they have small axles. If you are looking to buy a Grand National Rear end give me a call I have a line on one.

[455guy]

Yea, it's that whole 1000.00 for the gn rear I can't swallow!!

[455guy]

I have a 400 5 speed so the torque wouldn't be anywhere near that of a 455..Mainly street but will tow as well as hit the track once in a while.I could do stronger spiders and axels for less then 300.00 and I already have the rear with 63 k miles original so I might as well use it. A bud said he'd sell me a 69 gto 12 bolt for 500 but I hear it's not fun to get it in and set up. As well as being wider and worrying about tire clearance..

[Fast 82]

Yeah the rear end that my buddy has is going for $850.

[rolling money pits]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by 455guy:
Yea, it's that whole 1000.00 for the gn rear I can't swallow!! <HR></BLOCKQUOTE>


weeeeellll, think about the $$$ that will be spent if you blow the 7.5 up?

whats that old saying, an ounce of prevention is worth a pound of cure?

its entirely possible that a grenading 7.5 will cost than 1K to get fixed. or, you just get another 7.5, on the cheap, blow it up again, then the cycle repeats itself.

[Colin]

I have destroyed several 7.5 rears with MILD small blocks. Had one blow with a really mild 305........those rears are crap in my opinion.
I would find an 8.5 thats slose to the right width and weld the brackets from the stock rear to it.
I wouldnt even waste time using a 7.5 for anything but a V-6 or MAYBE a stock small block.
Even modified 7.5's with aftermarket axles, etc. probably isnt gonna last long behind your 400.

[Bill Eveland]

The last one I took apart , the pinion lost every bit of gear on it. This was just in a stock s-10 Blazer 4wd. I think they got stuck in the snow.
Don't waste your money on the 7.5.
The 69 12 bolt is about 3" wider, if your buying axles anyway, go with the 12 bolt aand have the housing narrowed or a bolt in g-body 9" housing. If your buying axles anyway that would be a great time to get the Moser axle ends that use the ford big bearing ends and stock gm brakes. The backing plate will have to be opened up for the bigger bearing.
South side machine lift used to have lower control arms to mount the older 10/12 bolts into a G-body.
Another friend of mine did something similar to what Colin was talking and used a rearend from a 68-74ish Nova and welded the backets on the housing. The brackets are available from some of the stock car building websites.

[Thumpin455_GTO]

I been rebuilding the 4th gen F body 7.5's for a while now. The guys in my club blow them up regularly. Sometimes we need a new posi, sometimes new gears. They have a torsen diff that has a non cone or clutch type posi. It knocks the teeth off the spider gears.

Do yourself a favor, either get a control arm kit to put in a A body 10/12 bolt, or gete a GN rear or moser/strange/aftermarket rear, be it 9" or whatever. You will be money ahead, trust me on that. Blow up a 7.5 two or three times and you can buy a new 12 bolt.

[455guy]

Anyone have a Southside mahine part number on the conversion corntrol arms? I've looked and find it.

[79GP6.6L]

Add me to the list of people who shot the spider gears through the rear cover! Cracked the differential and chipped a few teeth off the pinion gear too...all at once! That was on the stock unit. I could have been upset, but instead I thought it was pretty funny and saw it as a chance to upgrade.

My gas tank was not harmed, though.

[455guy]

I've looked and CAN'T find it..

[customizedcreations]

I ll second the blown up spider gear setup. I threw my gears out the back and through a fence at the track. Street tires , 2.41 gears and a stock 400 in a 78 GP. Ran a few 13's , put some stickier tires on the back , and bang. I installed a another 7.5 with a 2.73 posi, and went a whole year and then sold the car. Ran 12.50's no problems. Just let the tires spin a little and you ll be ok. If you hook up, thats when you have trouble.

[crossbreed455]

I have taken out posi, axles, gears, and the spider gears. I even had a TA cover on the rear. That was behind a 450 horse motor. I went to a 9" it has been in the car for 6 years not a problem with it. Do yourself a good thing and buy a 9 or a 12 and save money for the long road ahead.

mike m.

[WARPed]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by 455guy:
Anyone have a Southside mahine part number on the conversion corntrol arms? I've looked and find it. <HR></BLOCKQUOTE>


1328 is the SSM part number, if you can get one of these kits. I am building an 85GP and used a 68-72 12bolt. There is a guy that is now making the upper adapterbars for the 64-72 A Body. rears.