rear end size

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rear end size

Postby mirage_brat » Sat Nov 28, 2015 2:16 pm

Hi i was wondering if the 75 monzas had a 6.5 or 7.5 rear end
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Re: rear end size

Postby cammerjeff » Sat Nov 28, 2015 4:26 pm

The answer is YES, the 4 cylinder cars had 6.5 and the V-6 and V-8 cars had 7.5's (If I remember correctly) The easy way to tell the difference is look at the hardware that attaches the Torque arm to the rear end housing, if there are 4 bolts (2 top and 2 bottom) it is a 6.5. If there are 2 long bolts ant go thru the entire torque arm from the top to the bottom with nuts securing them on the bottom it is a 7.5"
With cars this old I never assume the rear end is original.
Jeff R

1971 Catalina Freeway Enforcer
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1973 4-speed Lemans Safari STOCK!!!!! 1978 Catalina Safari
2006 Mallet Solstice, 6.0 LS2, 6-speed manual
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Re: rear end size

Postby mirage_brat » Sat Nov 28, 2015 11:16 pm

Ok thanks for the helpful info :th: :th:
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Re: rear end size

Postby monzaaddict » Sun Nov 29, 2015 2:13 am

I believe all monza's had the 7.5. Most Vega's got the 6.5.
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Re: rear end size

Postby Monza Harry » Sun Nov 29, 2015 9:58 pm

mirage_brat wrote:Hi I was wondering if the 75 Monza's had a 6.5 or 7.5 rear end



cammerjeff wrote:The answer is YES, the 4 cylinder cars had 6.5 and the V-6 and V-8 cars had 7.5's (If I remember correctly) The easy way to tell the difference is look at the hardware that attaches the Torque arm to the rear end housing, if there are 4 bolts (2 top and 2 bottom) it is a 6.5. If there are 2 long bolts ant go thru the entire torque arm from the top to the bottom with nuts securing them on the bottom it is a 7.5"
With cars this old I never assume the rear end is original.

I had a 1975 4 banger with the 6.5" rear but I believe that was only '75 (maybe '76) afterwards the Chevette was the only use of the 6.5" in the Chevy line up. A quick search here will show you which year the switch was '76 or '77 I am pretty sure all '76 and up got the BIG little rear end (7.5") The Cosworth started in '75 and it received the 7.5" and the next year all the H-bodies did as well, ( IIRC ). On the rest Jeff has it the way I remember it as well. Harry
I'm not a hoarder I'm a preservationist 78 Monza Spyder (~Soon(ish +/- I guess) To Be 2+2 with Spoilers)
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Re: rear end size

Postby cammerjeff » Mon Nov 30, 2015 11:28 am

Harry,

That is the way I remember it, some of the very base model 76 Vega's and Astre's also got a 6.5 axle. But from what I know all Monza Bodied cars had the 7.5 axle from 76-80. I should have been more clear on that. I did part out a 75 Monza Coupe years ago. The only options I remember it having were Auto Trans & Power Steering. It Definatly had a 6.5" rear axle. I remember the torque arm being mounted with 4 small bolts. It was the 1st time I had ever seen that set up.
Jeff R

1971 Catalina Freeway Enforcer
77 Astre Formula, some day soon powered by a 215 Buick V-8
1973 4-speed Lemans Safari STOCK!!!!! 1978 Catalina Safari
2006 Mallet Solstice, 6.0 LS2, 6-speed manual
2009 Solstice Coupe, 2.4, 5-speed Manual
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Re: rear end size

Postby mirage_brat » Sat Dec 05, 2015 5:04 pm

My 75 does have the two long bolts that hold the torque arm on. Anybody know where i can get a posi unit for it also, perferably new
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Re: rear end size

Postby cammerjeff » Sat Dec 05, 2015 7:52 pm

If you want to convert it from 26 spline axles to stronger 28 spline S-10 axles it will be easy to find a new Posi unit. If you want to keep the 26 spline axles it gets more difficult. A good place to start here on this board is to PM monzaz He can get you just about anything axle related.
Jeff R

1971 Catalina Freeway Enforcer
77 Astre Formula, some day soon powered by a 215 Buick V-8
1973 4-speed Lemans Safari STOCK!!!!! 1978 Catalina Safari
2006 Mallet Solstice, 6.0 LS2, 6-speed manual
2009 Solstice Coupe, 2.4, 5-speed Manual
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Re: rear end size

Postby hammerdown7 » Sat Dec 05, 2015 10:01 pm

You can find Jim (monzaz) here http://www.jdrace.com
Great guy to work with.
Dick
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Re: rear end size

Postby Monza Harry » Mon Dec 07, 2015 9:18 am

I'm pretty sure Jim can source these either way, 28 spline http://www.summitracing.com/int/parts/d ... /overview/ or 26 spline http://www.summitracing.com/int/parts/d ... /overview/. You may pay more from Jim but I have found his prices competitive or better and SERVICE costs, usually a smart investment, from a guy who will take the time to help you figure out what you want/need. I have talked to Jim on the phone more than a couple of times and emphasize enough how good an experience it was, KNOWS his stuff! Harry
I'm not a hoarder I'm a preservationist 78 Monza Spyder (~Soon(ish +/- I guess) To Be 2+2 with Spoilers)
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