Hey Everybody: I'm new to this Forum & just Signed up. I'm presently working on a '72 Coupe & would like to know if anyone has done a TH700 R4 conversion on an eariler C3 ? What I'm looking for is anyone that has modified the Stock Trans Crossmember in order to mount the 700R4 in place of the 400 that's originally in the car?? Any & all help would be greatly appreciated. Also, if you got illustrations, drawings, of even pics of how to do the crossmember would be a big "Plus" & Help !

 

there is a company called bowtie overdrives and they have all the parts you'll need to do the conversion. another possibility, a 200R4 is actually the better trans. they were put behind the grand national, GNX and T type regals as well as the monte carlo ss.

http://www.bowtieoverdrives.com/index.shtml

 

Hey, "Bucky-Katt" Thanks for the reply. I already contacted BTO & I can't get one of their crossmembers until after the 1st of the year. I'm sort of pressed for time here. Besides, I think I can handle the mods to the stock Xmember & save the some odd 200 plus bills BTO wants for their xmember. Also, I read numerous comments about many guys having BTO's Xmember 'troubles' with installation. Maybe they're 'novices' & had the problems because of that, & maybe not.

I was just looking for someone that has done it & could give me a 'heads-up' on what it looks like & maybe tell me positioning, measurements & things like that, to give me a 'short-cut' in doing it, if you will.

 

thats good to know about them as i hadnt heard anything good or bad.

 

Yeah, I just figure, like anything else, it's a 50/50 posibility that one might encounter 'problems' when doing modifications & that doesn't neccessairly mean the Company's a 'bad' one.

When I talked to them on the phone. They seemed very nice & were helpful. BUt, unfortunately, they were out of stock on the one I needed [it figures]. They told me that they could fabricate one up right away. But the problem is, the Xmember is 'powder coated', which is great. But, they have to send it out for that to be done & that's where the time restraint comes into play. ANd, with it being the holiday season & all of that, I would venture to say, if I were to tell them
to send it as soon as possible, I wouldn't see it until Jan. I've got some time off right now to get this project done. But won't come the first of the year. Oh Well.

 

Most guy's just cut the crossmember flush to the frame, weld on steel plate end's and start drilling/bolting. Since you'll need the drive shaft shortened, same place can probably do the member welding too. I don't agree with using a 200R4, as much stronger 700R4/4L60 version's are availible. I've done this conversion a few time's, but if again would go 4L60E w/small computer module, as prices have come down. Much easier to set up with no TV cable or how to switch in converter lock up.

 

PM sent

 

I have a modified plate/shoe that mounts to the top and lower front of the stick shift/Muncie cross member, my '72 was a Muncie car....and so it's bolt on, I THINK the same one was used on the 400 automatic cars, at any rate if you have one on your car, this one will fit a 700 install....

IMO, the 200 is more suited to the car, for one thing you don't have to shorted the drive shaft by 2.5" and get it rebalanced, another trick is you need the thm350 output yoke for a later shark, the 400 is large diameter as was my Muncie....I forget about any adapting cross shaft for the yokes....they may not be same size....but no big deal as they are in stock at typical parts houses....

the typical 700/4L60e is a expensive for parts and hard to overhaul, many hard parts to buy, you going to spend about a grand in parts alone,..+ any labor you may have to do/buy..... the typical 200 will cost you about 1/2 as much...the 200 should set right on the cross member with no modifications, allowing you do ditch the entire mounting plate/shoe setup....

you will need a BWD brake light switch....I have lost the # to it, but it's a basic plug in swap for the OEM on your vette, but has a second switch section that will OPEN when you press the brake pedal, the stock section takes that orange wire to the white wire and puts +12 to the rear lights.....now that orange wire is always HOT, so you don't want that power to the other section, you need find a yellow wire or pink wire....yellow is good, that is a switched hot, like feeds the wiper motor....to one end of that extra switch section....the other feeds into the 4 pin square connector on the tranny, either 200 or 700 the electricals are nearly identical.....

now either one should lockup in 4th gear via a temp switch inside going to the 4th gear lockup switch.....mine is computer controlled from the GM DPFI computer I have in the car since way before the trannie conversions....

I had a 700 in my car....but the guy that built it put in a Superior/Fairbanks shift kit.....do not use that, use the TRANS GO shift kit and no other.....the 700 in there had a very premature 1-2 shift, not even 1/2 way through an intersection, and then would not stay in overdrive at WOT.....

I built my 200 4r in the vette now, and have no such issues with a TG shift kit in it....

Last winter I built my own 700 r4 for the Class C motor home project, removed a 350 tranny, for the overdrive.....modded the cross member.....but had to replace the sun shell, there is a version of the BRUTE you need, uses a torrington thrust bearing instead of the stock plastic junk.....that right there is over 100 bux....you need a TEN vane pump for either one....another 100 bux, converter is about 130 bux....

then the soft parts kit, and any other hard parts that don't check out....and of course a TRANS GO shift kit.....

I didn't bother with any input shafts as either 350 SBC engine I have is not all that high a HP rating....

PM with any questions.....as I may well miss this thread .....

 

davey, also ensure you get a 1987 or later core for your 700.

 

Just to be sure '88 up, and yes that IS a good point, I forgot....

 

I was fortunate enough to get the stongest 700R4 version, factory fresh from some GM buddies a few year's back. Still playing with the TV cable bracket angle I fabricated, as mentioned above, shift's to early. I did the Trans Go kit, and you need to know what you're doing here, as way more complicated than the 350 or 400 kit's. Even come's with an instructional video.

 

Here is a thread about the same question. http://forums.corvetteforum.com/c3-t...350-700r4.html I'm not sure if the company in the link still sells this perch. Give them a call!

 

Here is a link to another vendor that sells one. http://www.vetteworksonline.com/cata...roducts_id=177
Give them a call and see if it works with the 700R4 instead of a 4L60E. The tail housings are slightly different.

 

I've purchsed parts from Dan @ Vetteworksonline - good guy, very helpful. He also races Vettes.

 

Hey, Thanks much to everybody for all of their help in getting me a way to mount my 700R4 to my X-Member in my '72. I think I'll contact Dan @ Vetteworks & see how quick he can get me his Bracket Adapter. This One Looks Real Nice & I'm sure will do the trick.

As for everyone giving me advise as to which trannie to use. I mulled it over for awhile as to weather to use a 700R4 or a 2004R, as either trans will work for my application. Well, when a real good buddy of mine told me a good friend of his owns a performance trans shop & said he could get me a real good deal, I jumped at the opportunity. Well, after talking to his trans buddy, I was convinced that the 700R4 would be the best for me, even though I knew it would be extra work to put it in my '72, but it's nothing I can't handle. Plus, I got a 'Fresh' 700R4, ready to bolt in, with a gaurantee, ta boot, for 6 bills, Couldn't pass that one up. Also, my buddy's friend has been building trannies for 30 years & does everything from domestic to full blown out drag cars. So, I couldn't go wrong on this deal. Everybody I know that has put one of his 700R4's in their rides, weather it's a Vette or a Street Rod, or Street machine, has been pleased with it. So, I hope it all works out for me.

Thanks again