Removing bellhousing crossmember

[rbruno68]

I wanted to get member's thoughts on removing the bellhousing crossmember. I just bought a 63 C10 straight 6 with 4 speed granny gear transmission. I am planning on going with a small block and muncie 4 speed. Back when I first started driving, I had a 71 C10 that I had the same combination and kept the bellhousing crossmember. My muncie didn't have a support. I see a lot of people remove this crossmember and add a transmission crossmember. I am just curious on why people do this. Is it a strength/structural reason? Does it just make clearances for headers, clutch, etc easier? It seems very easy to find aftermarket or people making crossmembers. Back in the day, there were not that kind of options so I kept mine stock. Just curious on why people do it.
Thanks,
Rob

[MikeN]

I drilled out the rivets and removed the bellhousing crossmember on my 64 C10 in order to install a TH400, HOWEVER - previous to that, I installed a heavy duty Muncie 3-speed transmission and I did use the bellhousing mounts and no rear mount. It worked fine. This transmission is nearly identical and size and weight to your Muncie 4-speed.

It looks weird having a transmission hanging there in space with no rear mount, but the front bearing retainer in the transmission is a tight, machined fit to the circular opening in the bellhousing, so that plus the four large transmission-to-bellhousing bolts support the weight of the transmission just fine.

All that said, if you do choose to remove the bellhousing crossmember, it does not present any structural issues that I can see.

[AcampoDave]

My muncie is just hanging off (cantilevered as they call it) the cast iron bell. (I don't run headers.) I read up on both styles of mounting for a good while and the general consensus was that it makes no difference for the average manual 3 or 4 speed tranny.. The main thing is don't do both at the same time because it's too rigid.
I remember one guy specifically said that going with an engine/tailshaft mounting style would also put an enormous amount of weight at the point where the bellhousing bolts to the motor and nothing happens. Here's my thread from a ways back when I asked "the board " about it... http://67-72chevytrucks.com/vboard/s...d.php?t=705744

[rbruno68]

AcampoDave,
Thanks for the link. Sort of asking the same thing. In my first truck, it had a cast iron 3 speed that I am pretty sure weighed more then the muncie I put in it. I too never had a problem with the transmission hanging off the back. Actually made it easier each time I had to take it out and fix the synchronizers. Lol. I would just bandaid it together because I was young and had more time then money. So, taking it in and out was a little easier with no tailshaft crossmember. I will keep doing some research as well, but I would like to keep the truck as much the same as I can. I think my 6 cylinder bell housing would bolt up to my small block. But, I also think I have my original cast iron bellhousing some where from my original truck from 38 years ago. I am also going to get the headers and exhaust and other things and mock every thing up and then probably finally decide what I would do. Nice there are more aftermarket things out there now for these trucks then when I messed around with them in the past.
Thanks
Rob

[MikeN]

My 64 C10 was originally an inline 6 also. You can re-use the 6-cyl bellhousing, clutch, pressure plate, starter, and flywheel when converting to a small block Chevy, that is what I did.

You might have to get a new slip yoke for your driveshaft if you have a SWB truck. If you have a LWB truck with a two-piece driveshaft, I'm not sure how that changes things as far as driveshaft mods required.

[rbruno68]

MikeN,
I am sure you are right about the yoke. I might need a new or different driveshaft all together. The truck has the granny gear 4 speed and it might be shorter then the traditional 3 speed. So, I might need to find a different driveshaft. I haven't measured anything yet and could be completely wrong on that. Just did a quick look under the truck with it arrived at my house and the shaft looks longer then others.

[MikeN]

Driveshafts can be shortened and rebalanced fairly inexpensively at a local driveshaft repair shop. I've had it done several times.