CRG Discussion Forum

Camaro Research Group Discussion => Mild Modifications => Topic started by: KevinK on October 23, 2005, 02:20:33 AM

Title: 700R4 conversion in a '68
Post by: KevinK on October 23, 2005, 02:20:33 AM
 I've got a '68 RS vert (327/275) with a factory PG. When I do start the resto, ...I'm thinking about installing a 700R4 (or 200R4) trans for driveability. (This project is still down the road a bit, ...but it never hurts to research ahead of time...)
  Does anyone know of any good reference sites as for 'conversion' parts needed?
  I've been told about  Bowtie Overdrives ( ) and I do have a shifter w/Detents, ...but was wondering about driveshaft length, what crossmember to use, etc. etc.
Title: Re: 700R4 conversion in a '68
Post by: DougD on October 23, 2005, 02:25:40 AM
I believe a Turbo400 Crossmember would be right in the ballpark for a good fit on the 700.  Unless the gearing was a better fit, I'd skip the 200.
Title: Re: 700R4 conversion in a '68
Post by: tom on October 23, 2005, 10:11:56 AM
I have a 69 307 PG, and have been thinking along the same lines. I have been told the 2004r is a bolt in no mods swap. 700r4 I think requires cutting the drive shaft. Not sure I about that, but worth considering. I have aslo been told the 200r4 is not strong enough. Anyone have any experience?
Title: Re: 700R4 conversion in a '68
Post by: wtexz10 on October 23, 2005, 03:31:18 PM
I've got a freind who has a competition 200r in is 69.  When he bought the car I believe it had a turbo 350.  I don't think he had to cut the drive shaft.

Oh, he drag races the 69 and is consistantly in the low 11's.  A properly preped 200 is plenty tough.  Maybe thats why you'll find them in the Buick Grand Nationals.

Title: Re: 700R4 conversion in a '68
Post by: KevinK on October 23, 2005, 06:08:32 PM
...Thanks for the info so far...
  OK, ..."dumb" question,
   ...What IS the difference between the 200R4 and 700R4?
Title: Re: 700R4 conversion in a '68
Post by: 67ss350camaro on October 24, 2005, 01:20:27 PM
The 2004R is the easy swap.  With the 700R4 you will need to shorten the drive shaft.  I put a 2004R in my SS and have had no problems.  You can get them built to hold up better then the 700R4.  You will need to use a 400 cross member instead of the standard one.
I got my trans from
Title: Re: 700R4 conversion in a '68
Post by: 69 4 Speed on October 24, 2005, 08:08:43 PM
I've got a 2004R in a 72 El Camino that I got a few month ago. It has a shift kit and manually controlled lock up converter.  The motor is only a GoodWrench 350 but it is a great driver.   The transmission saw many miles in a 87 SS Monte Carlo and was not babied and it still shifts great.   I agree that they should be a relative reliable trans under all but the most severe driving.   

The Elky originally had a TH 350 and I believe the 200 was a bolt in operation.  Not sure.   Owner had been retired a couple of years and had moved out of state and left several project cars for his son-in-law to sell.      J.R.
Title: Re: 700R4 conversion in a '68
Post by: ntorp on November 03, 2005, 04:49:15 AM
I swapped out the TH350 in my '69 for a 700R4. Used the original crossmember but had to reposition it slightly and shorten the driveshaft a bit. With the manual lockup she works great and purrrs on the highway. A buddy is a tranny expert and built the 700R4 at his shop. He assured me the 700R4 was preferable to the 200. Find a good tranny shop and get them to build a good one locally rather than mail order. It will pay off if you have installation or setup questions.
Title: Re: 700R4 conversion in a '68
Post by: KurtS on November 27, 2005, 01:12:48 AM
To answer Kevin's question, the ratios are different:
Trans       1st    2nd  3rd  4th
TH350    2.52   1.52   1   N/A
TH400    2.48   1.48   1   N/A
2004R     2.74   1.57   1   0.67
700R4     3.06   1.63   1   0.7

2004R has a better 1-2 (and 2-3) ratio change. That's a big 1-2 drop with the 700R4.

I'd go with the 2004R personally.....
Title: Re: 700R4 conversion in a '68
Post by: go2fast on November 27, 2005, 04:55:45 AM
I have a shortened driveshaft for a 700R4 is anyone is looking for one.
Title: Re: 700R4 conversion in a '68
Post by: arocars on February 05, 2006, 04:45:26 AM
The 200-4r's were offered in lots of GM mid-sized cars, while the 700r4 was usually found in the 3rd gen Camaros and Firebirds. A 200-4r can be rebuilt to handle some serious horsepower.  There are plenty of them now available that will handle 450 hp and up.  I like the 200-4r swap over the 700r4 swap because the driveshaft doesn't have to be shortened and because you can adapt the t-400 crossmember.  Parts you'll need to put a 200-4r in a first gen Camaro/Firebird:  200-4r trans, 200-4r locking torque converter + 3 metric bolts, 200-4r dipstick and tube, speedo gears, floor shifter conversion kit and lens (so you can grab all four gears), gear lever (mounts on trans), trans bracket (mounts on trans), carb bracket, lock-up kit, and modified crossmember.  I have been informed that the t-400 crossmember does not exactly work without modification because the t-400's were used in big block cars, and big block cars used a different motor mount on the left (to clear the steering column), and that using an unmodified t-400 crossmember will 'tweak' the whole setup.  The solution is to cut the tongue off the t-400 crossmember and then remount it in the proper place, or buy an aftermarket crossmember made for this conversion.  I have read some poor reviews on some of these aftermarket crossmembers from people who have purchased them.  Comments like, 'poor fit' and 'poor paint'.  Plus, they're not inexpensive.  While not required, you might need to change your rear end gearing.  The 200-4r has a .67 overdrive.  So if you're running 3.08 gears, that'll drop you to 2.20:1 or so.  Which might be too low for your engine to make usable power.  .....  You might check out and for more information on this exact topic. 
Title: Re: 700R4 conversion in a '68
Post by: strat01 on March 18, 2006, 01:03:42 AM
i put a 700r4 from TCI, and it's called a streetfighter. had to change the flexi-plate and torque converter(stock stall) bought a cross-member for the 700 and shortened the driveshaft. get a pre-83 tranny w/o the puter hook-up. use the same vacuum lines and tranny cooling lines. you will need a new dipstick and tube. hook a couple of toggle switches and it's ready to go. gives great gas milage and it hooks up when you stand on the peddle.

Title: Re: 700R4 conversion in a '68
Post by: sdkar on May 04, 2006, 08:25:39 PM
I installed a 200-4r in my 68 and it was the easiest swap ever.  I had to get the TH400 crossmember, the shift plate and shifter plate from shiftworks, the torque converter lockup module from TCI.  I got the tranny from a buick (I think a riviera).  It cost me under $500 for everything.  It was easy to do and the results were tremedous.  The 200 had a luxury car shift feel so I highly recommend a shift kit to firm it up a little.  It was installed behind my smallblock.  Not super high horsepower, but the 200 handled it fine and worked great.

I have the original article from Chevy hi-performance magazine from several years ago.  I saved it.  It has the step by step instructions and the list of suppliers where to get the parts as well as the list of donor cars to look for to get the tranny.  I will mail this to you if you email me with your mailing address.


Title: Re: 700R4 conversion in a '68
Post by: KevinK on May 12, 2006, 11:43:45 PM
   ...just got the article you mailed, ...THANKS!
   ...I'll be sure to mail you 'something', a token of appreciation  ;)
   Thanks again...