Posi rear end

Trader history for Jbug.jbone (0)

69hurstolds

Comic Book Super Hero
Supporting Member
Jan 2, 2006
4,793
113
What are your plans with the 8.5?? If you're going drag racing with a 3 speed transmission (assuming automatic here), then you're likely going to be in a good sweet spot with 3.42. But if you're running a 4-speed auto, then hold out for the 3.73.
 
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Anubis

Royal Smart Person
Mar 30, 2012
2,308
113
West Michigan
What are your plans with the 8.5?? If you're going drag racing with a 3 speed transmission (assuming automatic here), then you're likely going to be in a good sweet spot with 3.42. But if you're running a 4-speed auto, then hold out for the 3.73.
I agree with this however if you have 400 whp or more like I do then 3.73 is overkill and you will not hook up unless you are on a prepped track. Even drag radials go up in smoke on the street.
 
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69hurstolds

Comic Book Super Hero
Supporting Member
Jan 2, 2006
4,793
113
I agree with this however if you have 400 whp or more like I do then 3.73 is overkill and you will not hook up unless you are on a prepped track. Even drag radials go up in smoke on the street.
Hooking up is a separate issue, but gear-wise in a stock or mild HP car, 3.73s are great with the OD transmissions. 3.42s are happier all around without an OD transmission. If you can hook the car, the 3 speed with 3.42 SHOULD give you the best trap times (governor settings not withstanding) between the two gear ratios if nothing else changes. If you're pushing a lot of power through the system, you're already making up for needing deeper gearing so 3.42 or even 3.23 may be right for your combo.

This is why people need to understand where they're going with their build (not just to the end of the dragstrip necessarily) BEFORE they build it so they can match their parts and pieces accordingly to get the best combination of stuff. You don't want your stuff working against each other.
 

lilbowtie

Comic Book Super Hero
Jan 7, 2006
3,398
113
Canton Mi
This is why people need to understand where they're going with their build (not just to the end of the dragstrip necessarily) BEFORE they build it so they can match their parts and pieces accordingly to get the best combination of stuff. You don't want your stuff working against each other.

My advice to people is to make sure all the components of your drive train complement each other for the purpose you want to achieve.
 
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BThurL

n00b
Jan 24, 2021
1
3
I’m in the Chicagoland area looking for a posi rear end, mainly looking for a “plug and play” kind of thing. Preferably 3.73 gears. Came across an add for an 8.5 3.42 gears but they were asking 1500$ I thought the price was too steep. Was it reasonably priced?

Willing to travel a bit to pick it up
I got a 86 cutlass t top I’m looking for 3.42 gears but this prices in Chicago so damn high I can just buy a roller
 
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