Guys, just got a 700R4 to drop in my '73 RS and after reading prior posts here and on NastyZ28.com I thought that the crossmember mounting was going to be easy. It doesn't appear so. I've got a TH350 c/m.

All of the other info I have read said that you either have to relocate the c/m back and mount the front c/m holes in the rear frame holes or turn the c/m around backwards.

I can't see how either method will work. Moving the c/m back will get you about 3" and turning it around will get you 12". It looks like the 700R4 mounting is about 7.5" farther back than the TH350. If I cut the mounting bracket off and rewelded it on the other side it looks like it would be close. I hate to do this but may not have a choice unless I want to spend big $ and get the BTO one.

Any other ideas? What did you have to do?

Thanks - James

The mount for a 700R4 is 2" aft of the mount for a TH350. You should be able to slide the crossmember this far.

onovakind67 - Not mine! Measuring from the edge of the bell housing to the mounts it is about 7.5" farther aft. I guess there must be different tail shafts for the 700R4.

http://chevyhiperformance.com/techarticles/p110352_image_large.jpg

The TH350 is on the left, 700R4 on the right. The 700R4 has a mounting surface that is part of the body of the tranny and isn't dependent on the tailshaft. If you have the mount on the tailshaft you could use either.

http://www.chevyhiperformance.com/techarticles/46278_automatic_transmission_overdrive_install/

That helps a bunch. I am measuring from the tailshaft mounting holes! I thought there were no other holes but maybe I was either drunk or stupid. I'll check tonight and hopefully have the other set. Thanks.

Nope - mine doesn't have the mounting holes in the case, only on the tail. See pic. What gives?

http://i26.photobucket.com/albums/c122/jm69ss/IMG_0911.jpg

try bowtie overdrives. I heard that they can custom make one for you. Give them the application. www.bowtieoverdrives.com

Good Luck!!

now i seen everything i rebuild transmissions and never seen a case like that before.:( without the 2 holes in case. maybe that came out of a caprice meaning cop car. they mounted on back bolts on tail housing.

looks like time to pull the welder out and make some fresh new burns in an old shirt...lol...i`m too cheap to buy a crossmember...i make all of mine, but thats just the cheap in me...buying one is much easier...recently, i put a 89 suburban drivetrain in a 57 apache pick-up...made it 4 whl drive with 86 blazer axles...i ran the front shaft thru a 6 inch .375 wall high carbon pipe that had crossmember welded to it...cut out section to fit pipe...when you do it yourself, you can be really creative...

if it helps at all, (I dont know how much diff. your car is to my 69) here is what my mechanic did to make my 700r fit, he notched out the crossmember to get at pan bolts. Just an idea. :)

http://www.carsbyjim.com/storage/Tranny/Thunder700r4001a.jpg
http://www.carsbyjim.com/storage/Tranny/Thunder700r4002a.jpg

you might have a Corvette tranny with a Caprice tailshaft.
but that's ok.
when i swapped from a TH350 in my Monte, i had to use the mounting holes on the tailshaft and a 94-96 Caprice trans mount that is offset forward about an inch to hook up to the TH350 crossmember, which was slid back to the TH400 holes that were already drilled in the frame. your Camaro should have a similar setup..

Only one set of holes in my frame. I didn't specify to the trans build shop what core to use so I guess this is what I get. I'll know better next time. I ended up cutting the trans mount bracket off the crossmember and rewelded it on the other side. It looks like it might still be a little short but hopefully there is enough adjustment in the slots for it to work. I've got her completely stripped down so a mock up fit is not practical right now. I guess I'll find out in a month or so when I go to reinstall the new engine and trans. Thanks for the help.

I did a quick Google and it looks like your trans is from a C4 'vette.