My DIY Low Budget GM 8.5 Build (using 2nd gen fbody rear)
08-08-2013, 11:47 PM
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Join Date: Aug 2009
Location: Staten Island, NY
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My DIY Low Budget GM 8.5 Build (using 2nd gen fbody rear)
Hi Guys, i have been poking around and posted on a couple of threads about building my own rear for a few dollars and spare parts I have in the shop.
How this all got started was that one late night in the shop and a couple of beers my buddy and I were looking online for a rear for my car and an idea popped into my buddies head so he pulled out one of the 2nd gen 8.5 Firebird disc brake rear I had and laid it next to a spare 4gen rear I broke playing around a couple of years ago and said dammm that's easy to retro fit and dam near as strong as a 8.8 or 12 bolt for pennies on the dollar. So today i took apart both rears to compare and see whats needed...
Note: : Before you guys wine and complain this is an exercise on what can be done with a few dollars spare rear and a welder I am not a drag racer and the car rarely sees the track just looking for something to handle the power I have and not have to worry about braking anything. Yes a 9 inch or a properly build 12 bolt etc is for the all out racer but for street use and some spirited driving i think this rear should handle anything I throw at it with a few upgrades...
List of things i am going to do...
1) Keeping the stock axle tube set up from the 2nd gen (the disc brake rear on these units are a exact match for the disc brake mounting brackets from the 4 gen .... (just unbolt from 4 gen and bolted right on the 2 gen axle tubes)
2) posi carrier has 28 spines going to see if i can re-drill axle flange for proper bolt pattern (if not order new ones)
3) will be changing the gear set to from 3.08 to 3.42 (i have a spare set of gm gears) or see if i can find a cheap set of gm 3.73 gears (will post a separate thread on the gear install
4) 2 gen rear is 4 inches shorter which is perfect for fitting some wider rims an tires (in the mean while will use a set of 2.5 inch billet wheel spacers to make up the difference for mocking up etc.
5) going to look into making of trying to machine the abs ring to see if i can make it work (if not no abs for know untill i can figure a way around it
6) might upgrade to a (c-clip eliminator kit) not sure yet (whats your opinion on that chime in)
7) yesss yess what about the torque arm ...
its going to look something like the link i am posting but no where near the $2300.00 price tag these jokers want (they have to be smoking crack in my book) http://www.pro-touring.com/showthrea...orque-Arm-kits
Budget is the name of the game (or best bang for the buck if i have to buy new parts) i am not trying to be cheap but i think this can be done for cheap and not allot of headaches
How this all got started was that one late night in the shop and a couple of beers my buddy and I were looking online for a rear for my car and an idea popped into my buddies head so he pulled out one of the 2nd gen 8.5 Firebird disc brake rear I had and laid it next to a spare 4gen rear I broke playing around a couple of years ago and said dammm that's easy to retro fit and dam near as strong as a 8.8 or 12 bolt for pennies on the dollar. So today i took apart both rears to compare and see whats needed...
Note: : Before you guys wine and complain this is an exercise on what can be done with a few dollars spare rear and a welder I am not a drag racer and the car rarely sees the track just looking for something to handle the power I have and not have to worry about braking anything. Yes a 9 inch or a properly build 12 bolt etc is for the all out racer but for street use and some spirited driving i think this rear should handle anything I throw at it with a few upgrades...
List of things i am going to do...
1) Keeping the stock axle tube set up from the 2nd gen (the disc brake rear on these units are a exact match for the disc brake mounting brackets from the 4 gen .... (just unbolt from 4 gen and bolted right on the 2 gen axle tubes)
2) posi carrier has 28 spines going to see if i can re-drill axle flange for proper bolt pattern (if not order new ones)
3) will be changing the gear set to from 3.08 to 3.42 (i have a spare set of gm gears) or see if i can find a cheap set of gm 3.73 gears (will post a separate thread on the gear install
4) 2 gen rear is 4 inches shorter which is perfect for fitting some wider rims an tires (in the mean while will use a set of 2.5 inch billet wheel spacers to make up the difference for mocking up etc.
5) going to look into making of trying to machine the abs ring to see if i can make it work (if not no abs for know untill i can figure a way around it
6) might upgrade to a (c-clip eliminator kit) not sure yet (whats your opinion on that chime in)
7) yesss yess what about the torque arm ...
its going to look something like the link i am posting but no where near the $2300.00 price tag these jokers want (they have to be smoking crack in my book) http://www.pro-touring.com/showthrea...orque-Arm-kits
Budget is the name of the game (or best bang for the buck if i have to buy new parts) i am not trying to be cheap but i think this can be done for cheap and not allot of headaches
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