Cascade Crew

blue89 · Posted: Fri Oct 17, 2008 9:33 am Post subject: Tranny crossmember options

So I'm having to make a crossmember for my car cause of the tranny I chose. I don't know much about the THxxx tranny's in camaro's, so could someone enlighten me? The one on spohn.net says its for a short shaft TH400

The one I am making looks close to this one for the lengths but can someone tell me how far the torque arm and tranny overlap? I just want to make sure I'm doing this right (read, not doing it wrong). It just seems like the tranny is hanging pretty far out from the subframe bolts. I have three holes like the spohn unit, I'm just worried that when I add the torque arm forces it will rip out due to the leverage it will have on the bolt holes.

Thanks!

Twilightoptics · Posted: Fri Oct 17, 2008 11:47 am Post subject:

Depends on where you put the block at. BBC are longer than SBC so you might have moved the trans back farther yet. If you're concerned about the leverage use thicker angle iron.

You could also move the torque arm mount farther forward with say a gusset between the bolted angle and the cross member itself.

On a T350 with a SBC you can buy a torque arm mount that mounts to 3 of the 4 tailshaft bolts.

You're in uncharted territory, now you just build it to make it fit.

That picture looks similar to what the T56 mount I made ended up like. Long ways behind the bolts. I used 2 sents of angle. One large and 1 small welded inside the large. It seems to be stiff enough for a 12 second pass!

blue89 · Posted: Fri Oct 17, 2008 11:55 am Post subject:

Oddly enough, the BBC with its stock clamshells and stock SBC kmember mounts sits EXACTLY the same as a SBC in the engine bay. I was pretty amazed too. The bellhousing is just a smidge forward of the firewall. However, the motor is forward enough that I cannot use my stock V6 single fan radiator setup.

I saw that bracket on summit that bolts to the output shaft housing. I'm going to try to use an end-link to mount the torque arm to the crossmember. Seems easy.

As long as noone thinks that the brace is too far out I'll continue on. I have some pieces I'm going to weld tonight so I'll take a pic when it's together.

chevymad · Posted: Fri Oct 17, 2008 5:15 pm Post subject:

BBs are the same length from motor mounts back. They just stick out further forward. I switched my chevelle back and forth from sb to bb many times. Never could keep the 396 running long,, or just couldnt afford to feed it.

blue89 · Posted: Mon Oct 20, 2008 7:29 am Post subject:

Well here it is. My version. Just have to do the torque arm mount but that should be nut and bolt.

Twilightoptics · Posted: Mon Oct 20, 2008 7:51 am Post subject:

How did you end up with the tranny mounting pad at an angle?

blue89 · Posted: Mon Oct 20, 2008 7:59 am Post subject:

It's not, its level. I bolted that cross piece to the tranny, side brackets to the car, then welded. But since the subframes are all kitty-whompus it needed a jog in the brace or a really low passenger side bracket like the spohn piece. Since I did it with the jog I didn't need that raised tranny mount platform like spohn.

If anything it might be a little high but the pan seemed pretty level. Does it still look weird or make not sense? I hope I didn't do it wrong.