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58 chevy trans swap?

I love my Chevy Chevette!
Posts: 2
Joined: 09/09
Posted: 09/25/09 10:26 PM

Hi, I am new to the Chevy Forum.  Question for the experts.  I got a 2 door 1958 Bel-air w/ 350 TH350 and want to swap to an overdrive 700r4 or 200r4.  Has anyone done this on a 1958 Chevy?  I hear the 200r4 is the same length as a th350, so is it a direct bolt on?  Can you use the same crossmember too?  How about rear ends, I want to swap in a posi, which rearends can bolt into a '58 if any?  Thanks. Jeff  

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Everything in my driveway’s a Chevy
Posts: 537
Joined: 06/08
Posted: 09/26/09 08:45 AM

The 700R4 is a very good trans, I put one in my 69 Malibu. The original crossmember just had to be moved back 2" and the driveline had to be shortned, not a big deal. The 1,2 gears are lower than in the 350 so acceleration will improve as well as gas mileage, my 350 in the Malibu is getting 20+ mpg (hiway) You can put a posi differential in your existing rear end, no housing change necessary unless you REALLY want to.  

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I mow my lawn and find Chevys
Posts: 2253
Joined: 07/08
Posted: 09/26/09 03:26 PM

The stock rears in 58 chevys were OK. I raced one quite a bit with a 4.56 posi in it, way back when, and it never failed. Posi's did come stock in some 58s so they are available.  

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I love my Chevy Chevette!
Posts: 1
Joined: 01/10
Posted: 01/27/10 01:48 PM

I have a similar question.  My Delray was a 6cyl. The previous owner moved the engine mounts back about 2 inches and installed a 350. Probably to use the original 3 speed. It now has a Muncie 4-speed. I would like to move the mounts back to the original location. Would I have to fabricate a transmission mount and extend the drive shaft? Also the bushing at the top of the rear end has been broken. Any suggestions on replacing the housing or complete rear end swap? Thanks in advance.  

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