Cutting torsion bar crossmember to make room for transmission (TKO)

[XH29N0G]

Part of my ongoing saga to correct the driveline angles after an older tremec tko install now has me looking to modify the tunnel.  I have now had a good look at where the front shifter cover plate of the TKO transmission hits the tunnel, but I also see that the rear shifter cover plate hits the torsion bar cross member. 

My situation is that I need to raise the transmission at least 1" to get the angles better, and some cutting will need to happen.

Will anyone who has done this give advice on how to proceed?


Immediate questions that come to mind?.  If the cross member is cut? does an extension need to be welded in place?  Are there prefabricated extensions? Have people modified the tailshaft by grinding down the rear shifter cover?  It looks like American powertrain may have done this.  I wonder if they would sell their tailshaft. I know the questions are a lot.  I thought I would put them down in case there were answers.

[John_Kunkel]

This might help:

http://www.hurst-drivelines.com/mopar-1966-70-b-body/

http://www.hurst-drivelines.com/installing-a-tremec-transmission-into-a-1970-superbee/

[XH29N0G]

John,

Thanks.  There is something on the link that is relevant to my issue.  The link has a picture of a modified tailshaft housing (they have milled the third shifter box down)  Compare the top picture below with the one underneath and the yellow box. 

The kit I have is one of their's (an older one).  I sent them (and a few other places) a question about the milled tailshaft housing because that would make it a bolt in (with some tunnel cutting and massaging (which I did this weekend to deal with other places where there are (were) contact). 

The next step is either finding someone willing to send a modified tailshaft, have the one I have milled, but I worry about that, or modify the upper part of the torsion bar crossmember (presumably by welding in pieces).  I also saw a kit done by toddron retorations (lower picture of a their solution for a T56) for A bodies.  They do not make something for B bodies, but say they have considered it.

Anyway,  I have a bunch of requests out to get more information and am hoping one of the companies with the kits will sell a tailshaft housing that has been modified or give me advice on how to do this.  I would prefer that over having the upper part of the cross member cut and then rebuilt, just because I don't know how strong a rebuilt one would be.  But if that is the only solution, then that is what I will do.

Thanks

[cdr]

Not the same trans, but this is what I did for my a518, along with the kframe spacers

[XH29N0G]

CDR,  I am not familiar with the 518, so I have some questions.  Did you mill part of the housing to make it fit?  It also looks like you have modified the upper arch that connects the right and left sides of the torsion bar cross member.  This is one of the options I am facing, but I would prefer to mill down the place on the transmission where it interferes with cutting the upper arch and fabricating an alternative to what the arch is supposed to do.  Thanks.

[cdr]

Yes to all,  & also put torque boxes & weld in frame connectors to tie it all together.

[XH29N0G]

I have several updates:  

1) I tried to contact several different companies that are currently selling Tremec transmissions with modified tailshafte to ask about modifying the tailshaft on mine - only HDC and SST (Silver Sport Transmision) replied, and only SST is set up to do the modification.  I am very appreciative of their responsiveness and willingness to work on a set up that is not one of theirs.  

2) I was a little worried about setting up the car high enough (I do not have a lift) to remove and reinstall the transmission, so stopped by one shop I have heard good things about to ask if they would help.  The answer was no because it would tie up the shop too long to send it out and wait.  Not the answer I wanted to hear, but I appreciate their frankness and then decided to look into it again myself.

3) I made a transmission cradle for my floor jack, lifted the car, and removed the transmission today.  I have no idea how I am going to get the geometry right, because the engine does not want to rotate enough to align the input shaft and the floorpan and crossmember (even looking forward to the modified housing) will not easily clear the housing.

So I have made enough progress to send the transmission in (Good), but do not yet know how I will reinstall the transmission when it comes back.

I am assuming that the people who did the restoration installed the transmission already attached to the engine from the front or from the bottom.  I am concerned about being able to do similarly.  I have an old engine hoist (from my dad), but have never used it. 

[XH29N0G]

Just an update.  Silver sport transmission came through with the modifications of the transmission housing.  I managed the reinstall (twice - first time I forgot the throwout bearing which I realized when heard a thump and my daughter said the pedal just went to the floor.  The transmission is up and shimmed (I have a little more than an inch).  The tail looks to be down by a little over 2 degrees, the driveshaft front came up so it is now down by almost 2 degrees, and the differential has been at about 2 degrees (all very close to parallel and I am hoping it keeps going well for the maiden trip after the change).   Now the collectors don't hang low (like a continental soldier) and instead tuck up under the body.  This meant I have had to reroute one pipe around the crossmember.  I am so far very happy with this.  I am also appreciative of the folks at Silver sport.  It wasn't one of their units, but they were ready to do business, prompt, and their work looks good.  I'll know for sure once I get the car back on the road - hopefully this weekend. 

[Derwud]

Just an update.  Silver sport transmission came through with the modifications of the transmission housing.  I managed the reinstall (twice - first time I forgot the throwout bearing which I realized when heard a thump and my daughter said the pedal just went to the floor.  The transmission is up and shimmed (I have a little more than an inch).  The tail looks to be down by a little over 2 degrees, the driveshaft front came up so it is now down by almost 2 degrees, and the differential has been at about 2 degrees (all very close to parallel and I am hoping it keeps going well for the maiden trip after the change).   Now the collectors don't hang low (like a continental soldier) and instead tuck up under the body.  This meant I have had to reroute one pipe around the crossmember.  I am so far very happy with this.  I am also appreciative of the folks at Silver sport.  It wasn't one of their units, but they were ready to do business, prompt, and their work looks good.  I'll know for sure once I get the car back on the road - hopefully this weekend. 

Just got an e-mail about your Swap.. Very cool!!