1968ragtop

I pulled the 2 sp glide out and am installing a th400. Is the trans cross member the same between these two transmissions? Or do I need another cross member from a big block car? I'm mostly interested in if the mounting location on the cross member will be at the same height because with the glide cross member, the th400 looks like its sitting too high in the tunnel!
TIA

joe68h/o

Be sure you are uaing a tubo 400 trans mount as they are different from the one used on a turbin 300 trans.

1968ragtop

Well heres what happened. I installed the trans on the 68 th300 cross member with a th400 tranny mount. The trans was really tight to the tunnel, it looked like the drive shaft would almost be scraping the tunnel, so I modded the cross member, welding in 1/4" steel to lower the nount location 1" now I think I lowered it too much probably 1/2" would have been enough. I think I'll weld some steel onto the cross member mount location to shim it back up again. Just wondering if anyone has come across this before? If its too low the only problems I see is more stain on the motor mounts a slightly different angle on the driveshaft to pinion and the pan hanging a little lower.

TripDeuces

I did this same switch on a 66 about two weeks ago. I'm not using an original cross member though but the tail of the TH400 does seem higher and I am using a TH400 mount. It's not hitting against the tunnel at all and works just fine. In fact I'm no where near that tunnel. I can put my hand easily on top of the trans. Maybe others on here may know if different cross members were used between the two transmissions.
I would suggest not modifying that cross member by welding on it or the frame. It's not like that stuff is a dime a dozen nowadays.

joe_padavano

The TH400 was a factory option in 1968 (yeah, in the 442, still a Cutlass body and frame). The crossmembers are the same. The holes for the rearward TH400 crossmember location are already drilled in the frame. This is a complete bolt-in operation. There should be no need to do any cutting and welding. You DO need to change the front and intermediate e-brake cables due to the different crossmember location.

TripDeuces

I actually found a way around the brake cable problem. If there is a boat place near where you live they make copper/aluminum crimps for cables. You find your new length, cut the cable and put a new crimp on. They are 1/8 inch and I used two for safety. Most hardware stores have these also. In my state they are forbidden by law to do it for you but they will allow you to use the tools no problem. I used the original front cable and just shortened the intermediate one. I would have preferred a steel crimp but they weren't available so I used two copper ones.

joe_padavano

Sorry, but I don't understand why someone would want to cut corners here. For the 68 in the O.P., RockAuto has the correct cables for $24 for the front and $16 for the intermediate. It's not worth screwing with something mickey mouse to save that kind of money.

TripDeuces

I hardly consider it mickey mouse but I suppose you're entitled to your opinion. It actually came out quite nice. My $5 fix vs your $40 plus. Not to mention the time waiting for the product to arrive. I'll call the labor a wash.