2004R Cross Member
Thread Starter
Racer
Joined: Apr 2006
Posts: 322
Likes: 0
From: Rockford MI
2004R Cross Member
Has anyone swapped a 2004R into a 78 and used the original crossmember? If so did you have to modify it?
I have searched the forum and found info indicating both ways, that is has been done and that you need the BTO crossmember, so I'm looking for first hand experience.
I have searched the forum and found info indicating both ways, that is has been done and that you need the BTO crossmember, so I'm looking for first hand experience.
Drifting
Joined: Jan 2004
Posts: 1,991
Likes: 3
From: Piscataway NJ
I looked in the GM parts and illustration manual. Th 68-79 auto crossmember is the same. It appears that you eliminate the small trans suppurt bracket for the th350 and use the two upper holes in the crossmember that the th400 used. The lenght for the 200r4 from the face of the bellhousing to the mount is 27 in. The 400 is 26 15/16. So it appears to be a go. I am doing this for my 77.
Race Director
Joined: Jul 2004
Posts: 12,703
Likes: 329
From: Scottsdale Arizona
If the 68 to 79 is the same cross member, then your 79 should have a TH400 rather than a TH350. If so, your crossmember should work fine without modification. The TH350 crossmember won't.
Race Director
Joined: Jul 2004
Posts: 12,703
Likes: 329
From: Scottsdale Arizona
Originally Posted by 78anniversary
So if I understand this correctly, the crossmembers are the same for the TH350 And TH400, the 350 just has a support bracket that needs to be removed and the 2004R should work?
Melting Slicks
Joined: Aug 2003
Posts: 2,135
Likes: 2
From: Dayton Oh
Unless I missed something obvious during my 79 TH350 to 2004R conversion last winter, the 79's TH350 xmember would not work. According to memory, the TH350 xmember holes were about 6" too far forward. I used Bowtie's xmember and was an easy install and highly recommended by me.
Melting Slicks
Joined: Mar 2006
Posts: 3,443
Likes: 2
From: McDonough Georgia
Originally Posted by marshrat99
Unless I missed something obvious during my 79 TH350 to 2004R conversion last winter, the 79's TH350 xmember would not work. According to memory, the TH350 xmember holes were about 6" too far forward. I used Bowtie's xmember and was an easy install and highly recommended by me.
The th350 WILL work I just did a th350 to 200r4 on my 76 but in doing my research I read that in 79 they changed the crossmember and they will not work for the 200r4.Do a search on it you will come up with a good bit of info.
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Drifting
Joined: Jan 2004
Posts: 1,991
Likes: 3
From: Piscataway NJ
The th350 used a small bracket that bolted to the crossmember by four bolts. Two in front of x member Two in top of x member. If you dump that bracket you will use the two holes in the top of the crossmember. 69-79 thm350 and 400 used the same crossmember. Look through the square hole in the bottom of the crossmember, you will see the two holes you will use.
