[neal64ss]

Planning to convert my 64 chevelle from M20 manual to either 200-4R or 700-R4 this spring. Motor is a 396 with oval port heads, q-jet, headers, mild cam. I don't race anymore and want to be able to take car on extended trips without a headache from the road noise.

Been doing a lot of research, great info on this board by the way, and would like some advice on a few things.

1. Is the 200-4R the same length as my muncie M20 and will the tailshaft yoke interchange between them? Will the yoke interchange with the 700-R4? I know it will be longer in length.

2. I am thinking about getting a tranny from a salvage yard, installing it myself, and driving until failure/problems arrise. Has anyone else done this, what kind of luck did you have? I like the 200 for the gearing, I have loads of torque currently and don't think I need the lower first gear ratrio of the 700, also like the fact that the 200 has higher overdive ratio.

3. Would I be "wasting" my money to have a tranny overhauled by a local shop with standard non-performance parts? I ask this becuase it seems some of the performance parts are expensive and I am trying to keep the budjet under 1K for the swap.

Thanks for any help, I love reading these forums, I always learn something new. Sorry for the long post.

 

[Guest]

Neal,
Doing an OD swap for $1K is asking alot and honestly, you would be cutting corners.
I wouldn't expect a wrecking yard 700 or 200-4R to live long behind even a mild 396.

Just the parts to build either one of these transmissions to live reliably is about $500-800 and that doesn't include a converter, retrofit components, driveshaft mods, fluid, etc.

I have a '74 Nova in the shop now that I am doing an I-6/TH350 to V8/700R4 swap. $90 to shorten the driveshaft, $150+ for the crossmember, $18 for the TV cable, $150 for the converter, $10+ labor to bend new trans lines, $40 for the linkage kit, and I still haven't accounted for 12 qts of fluid, TV cable brackets, lockup control, etc.
I built the 700-R4 and it would be over $1000 just for the transmission.

 

[68start]

Your question is in my head also. Just yesterday I picked up the good #732 700r4 for $100 in "good" shape (I hope). I also have a mild 396 with 3:08 gears. Lots of highway driving for me. I'm also thinking about "giving it a try". Might attempt to do some upgrades inside the tranny myself. Lots of info on how to rebuild on the internet and may not be to bad to do. Mine is going to sit for awhile until I feel comfortable and ready to make the swap. I might just end up putting it in my wife's 68 camaro behind a mild 350, but it currently has 2:73 gears. Looking forward to hearing some input.

 

[neal64ss]

Well I now have a "recently rebuilt" 700R4 in my possesion. First thing I have noticed is that it has an electronic speedometer output.

What are the best ways to convert? Should I put an electronic speedo in the dash or convert the tranny to driven gear?

The speedo in the dash broke about a month ago.

 

[Bowtie70ss]

I have one piece of advice...Go to 700R4.com(Bowtie Overdrives) and buy a TV made easy kit. If you do not have EXACTLY the right TV adjustment and geometry then you will burn it up in less than 50 miles. The TV made easy kits are specific to the type of carb you are running and fit very nicely. I love overdrives and if I wasn't set on a manual right now then I'd have one. BTW those 200R4's can be built to handle 1500HP such as found in those insane 7 and 8 second turbo Buicks. The 200 swap is easier because you shouldn't have to cut the driveshaft or anything but in stock form they are relatively weak.

Dave

The 700 uses the same type of drive gear as a THM 350 or Muncie but the same driven gear as a THM 400. Convert it to mechanical unless you really need a speed sensor for some reason.

 

[neal64ss]

So I can remove the electric sensor, replace it with the drive gear from my muncie and get a driven gear for a 400 and be done or is there more to it. Does anyone know if a kit is made to tackle this? Should I just swap out the tailshaft with a mechanical drive type? Nobody doing the electric speedo thing?

 

[Bowtie70ss]

The tailshaft is the same. Remove the speed sensor and install a gear housing and gear. The THM400 has the large housing like the 700R4 and the output shaft size is the same as a muncie or THM350. Lots of info on this stuff out there and Bowtie Overdrives are a great help.

Dave

BTW the gear housings have a specific range of speedo gears that can be used and it is imprinted on the side. There are formulas online so you can figure out exactly which drive and driven gears you need as long as you have the tire diameter and gear ratio.

 

[neal64ss]

Is this all I need to convert to mechanical speedometer output?

http://cgi.ebay.com/ebaymotors/700R...ryZ33727QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Will I need to tilt tailshaft up during this change to keep fluid from pouring out?

 

[136679ss]

Is this all I need to convert to mechanical speedometer output?

http://cgi.ebay.com/ebaymotors/700R...ryZ33727QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Will I need to tilt tailshaft up during this change to keep fluid from pouring out?

Yes, but the speedo gear will be specific to your tire diameter and driven gear. Empty the trans before installing, if you tilt the tail up the fluid will still poor out of the front pump housing. Better to pull off the tailshaft, as you'll need to know the number of teeth on the driven gear as well.

 

[Bowtie70ss]

If you have a speed sensor now you will also need the drive gear and retainer. That is the one that slides on the end of the output shaft. The parts you linked to are correct if the tooth count works out for you.

 

[Steve1972]

http://www.geocities.com/crosley_az/700spd.htm

Here's some good info on the electronic to cable conversion.
Steve

 

[neal64ss]

:beers: Thanks Steve, that is exactly what I need. :thumbsup: