my question is i have 10 bolt rearend stock in my 85 monte standard it had a 4.3 v6 not sure what gears it has, i got a 383 stroker now 350 turbo with shift kit high stall should i just put a eaton posi kit 373 gears or i can keep it standard and put a locker to make it posi anything would help thanks.
should i go posi track for 383 ?
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a locker would not be much fun making tight and slow turns and on the street and might be a lil dangerous on the highway because the wheels will spin the same speed in a curve. i would get the eaton posi unit if it was me good luck.
Theres a good chance your car has some pretty lame gears as far as performance is concerned since it was a factory V6 car. I would never run a full locker unless it was a strip only car. That being said you might wanna start looking for an 8.5", 9" Ford, or 12 bolt GM because theres a more than good chance that the 383 will grenade the stock 7.5". Just sayin...
-83MONTESS- said:
well i was told that rear end would work but its just the gears i should worry about. i have a stock 350 turbo with high stall converter i dont even know if that would hold out. My main concern is the gears and rear axle, i mean if all i need is a eaton 373 posi kit im fine with that i just dont want to have to switch the rear axle never done it . Money is not a problem but im not wanting to go all out either its going to be a daily driver once in a while drag raced but if that v6 rear axle wont work i would just get a monte ss rear end.
A rear from an SS will be exactly the same as what you have now. Different gears, but the same strength, which isnt great. Depending on what your power output is, you may make that 7.5 survive. but you will need more than just gears to have some piece of mind that it wont break. I debated building my 7.5 also, and decided it probably wasnt worth it.
I believe some of the 4.3s came with 3.08s which would be an ideal gear if you are stuck with an old three speed and its for a driver. Especially with higher torque and generally lower torque range of a stroker 383. You should check it may be taller but the v6s often came with a better gear than the v8s to help them out in the acceleration department.
I also would recommend an Eaton. I had great luck with mine and was impressed with the quality over other units.
X2 that a stock 7.5 is weak for behind a 383 especially if you have a high stall and plan to add some traction mods and or drag radials. But if you fortify it and keep your car off slicks and a drag strip you should be fine. Moser makes 28 spline axles for the 7.5/7.625 and you would need to do this before adding the posi . You can also use a solid spacer instead of a crush sleeve and weld the axle tubes for strength. You just put a good bead around where it mates to the housing. Last a girdle cover such as made by http://www.taperformance.com then click on rear end girdles then GM 7.5 10 bolt.
I also would recommend an Eaton. I had great luck with mine and was impressed with the quality over other units.
X2 that a stock 7.5 is weak for behind a 383 especially if you have a high stall and plan to add some traction mods and or drag radials. But if you fortify it and keep your car off slicks and a drag strip you should be fine. Moser makes 28 spline axles for the 7.5/7.625 and you would need to do this before adding the posi . You can also use a solid spacer instead of a crush sleeve and weld the axle tubes for strength. You just put a good bead around where it mates to the housing. Last a girdle cover such as made by http://www.taperformance.com then click on rear end girdles then GM 7.5 10 bolt.
I know this is an older post but the replies are right on, the stock unit will grenade on you as they were barely capable behind a Monte Carlo SS with the L69 HO motor! Also, having tall gears (like a 3:08) will put even more strain on it!
My 1987 Monte Carlo SS has a 6-speed manual and a TPI full-roller 406 under the hood, right now I am running the stock SS rear (it does have posi and a 3:73 ratio) but the only thing I have that is preventing a blown rear is the over 500 hp causes instant wheel-spin! If I ever 'hooked up' the rear would be trashed within seconds!
It isn't hard to replace the entire rear end. You can purchase 12 bolt GM or Ford 9" that already has all the proper brackets so it bolts right in!
This is just a matter of my opinion but I would go with a 12 bolt GM as it takes less horsepower to turn than a Ford 9" does.
Also, I don't think he meant a 'locker' or spool, I think what he was referring to was a Detroit Locker, these can be used on the road (I had one and ran it for years in a Dana 60) the Detroit Locker will lock up solidly but will allow turning without chirping or sliding. A friend of mine built a 'poor mans' spool in a 1954 Ford with an ex Nascar motor in it by welding the spider gears!! Very dangerous but it locked the two tires for sure!
Good luck and have fun!
My 1987 Monte Carlo SS has a 6-speed manual and a TPI full-roller 406 under the hood, right now I am running the stock SS rear (it does have posi and a 3:73 ratio) but the only thing I have that is preventing a blown rear is the over 500 hp causes instant wheel-spin! If I ever 'hooked up' the rear would be trashed within seconds!
It isn't hard to replace the entire rear end. You can purchase 12 bolt GM or Ford 9" that already has all the proper brackets so it bolts right in!
This is just a matter of my opinion but I would go with a 12 bolt GM as it takes less horsepower to turn than a Ford 9" does.
Also, I don't think he meant a 'locker' or spool, I think what he was referring to was a Detroit Locker, these can be used on the road (I had one and ran it for years in a Dana 60) the Detroit Locker will lock up solidly but will allow turning without chirping or sliding. A friend of mine built a 'poor mans' spool in a 1954 Ford with an ex Nascar motor in it by welding the spider gears!! Very dangerous but it locked the two tires for sure!
Good luck and have fun!
Okay so I did some research the 9” ford rear axle with Moroso spindles comes out to be like 900 which is not bad but question is do I really need it for a street/everyday driver? I will be using a built 350 turbo with a 3500 stall converter, aluminum driveshaft, so do I really need that rear end ? and well I could I just do a limited slip on the stock differential? Overall I am pushing 450 to 475 hp torque around the same.
My take on it is that the 7.5 rear you have now will not "instantly grenade" BUT....if you repeatedly hook up hard with that kind of power it will only be a matter of time before you wreck something. My 1st G body had the 7.5 and it took a lot of abuse and never failed. If you don't mind tire spin go with the 7.5, otherwise invest in something stronger. I'm surprised you can get into a Ford 9" for under 1K. The 8.5 442 or GN rear is also a good option.
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