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Old 02-27-2008, 09:08 AM   #1
rigon4
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81 2wd blazer rear end??

the tag in the glove box says standard rear axle. its a 12 bolt and would like to know what gears are in it. it has a 250 i6 and th350 can i get away with a mini spool and gears or do i have to run a full spool 373 or 411 gears and c clip Eliminator.
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Old 02-27-2008, 09:52 AM   #2
Twisted78SS
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Re: 81 2wd blazer rear end??

Well that depends you intended usage, Can you provide more info and or what your plans are. Might help in providing a response. Also, was there a 3 digit code (an RPO Code) that may decipher it for you.

You can see a pretty good list here
http://www.c2e.info/rpocodes/
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Old 02-27-2008, 03:38 PM   #3
rigon4
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Re: 81 2wd blazer rear end??

well i have a 425 horse 355 and built th400. I want to make it a street/strip truck some thing i can drive a couple times a week and take it to the local 1/4 mile drag strip on sunday
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Old 02-28-2008, 06:27 AM   #4
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Re: 81 2wd blazer rear end??

Cool, sounds like a great combo.

With the turbo 400, and depending on the torque output of your engine you may get away with 3.55's. With 3.73's and 4.10's/4.22's your rpm's at freeway speed will be creeping up pretty quickly. As for a spool and c-clip elim, I have run a spool on the street before and hated it. I have never had good luck with c-clip eliminators not leaking when used alot. Now I run a posi unit (in my case a Power Loc since I have a Dana 60), but with the truck 12 bolt, many will say the pinion is the weak link due to its shaft size and that the 30 spline axle is only good to some magical horsepower number. i have seen two trucks grenade the rear axle in stock form at the track, but you never know. If you upgrade the axles, and find a good posi unit I think you can go both street and strip with relatively good reliability

-Drew
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Old 02-29-2008, 08:08 PM   #5
rigon4
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Re: 81 2wd blazer rear end??

ttt ok that site says standard rear end. so what was the standard gears??
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