Rearend & Transmission Identification
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Joined: Sep 2009
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Rearend & Transmission Identification
Hello,
I have a 1989 RS IROC, yes It's an IROC clone from an RS. However, when I bought the car the guy I bought it from flaked out and never gave me the info on all the modifications he made. So, I need to find out how I can id the rear end and trans. The original trans was a stick and now it is an automatic. The rearend is out of a 4th gen.
Thanks
Nikki
1989 RS/IROC
I have a 1989 RS IROC, yes It's an IROC clone from an RS. However, when I bought the car the guy I bought it from flaked out and never gave me the info on all the modifications he made. So, I need to find out how I can id the rear end and trans. The original trans was a stick and now it is an automatic. The rearend is out of a 4th gen.
Thanks
Nikki
1989 RS/IROC
Member
Joined: Aug 2008
Posts: 428
Likes: 5
From: Auburn, MI
Re: Rearend & Transmission Identification
If it's a 4th gen rear, then it's a 7.625" 10bolt. Should have 28 spline axles and most likely a limited slip.
If the transmission is a 4 speed with overdrive, then it's probably a Th700R4. Could be a 4l60E or Th200R4, but I doubt that. If it's a three speed, odds are it'll be a Th350. Might be a Th400, unless you have some serious motor under the hood....it's overkill.
If the transmission is a 4 speed with overdrive, then it's probably a Th700R4. Could be a 4l60E or Th200R4, but I doubt that. If it's a three speed, odds are it'll be a Th350. Might be a Th400, unless you have some serious motor under the hood....it's overkill.
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