I am switching a 56 Chevy truck from the original 3 on the tree to a 700R4 and I realize I have to add the tranny support however what about the mount at the bellhousing / rear of the motor? Do I need to add a support and if so, does anyone offer one off the shelf?
Motormounts and a trans cross member is all you need. Speedway, Classic Parts, American Classic Parts and numerous others sell a bolt in version for our trucks. You'll need to cut out the rear support that's in it now. It's riveted in but not too bad of a swap. I originally had a 3 speed manual, swapped to a TH350 and eventuallt to a 200 4R to get overdrive. The 200 is the same length as a TH350 so no driveshaft shortening. Did have to move the trans cross member back about 5 inches but that only required new mounting holes.
That works if you don't have the original 56 engine, which has no provisions for side mounts... The driveshaft yoke is a different spline. But yeah, it's a pretty straightforward swap
I did a 57 pickup 350/350 and only used a 70s style camaro/nova etc. type crossmember laying perfectly rite in the inside of the frame channels I just had to drill holes (as I think I remember)while using the original front stool motor mounts, I also done 2, 55 cars the same way {but had to make a couple brackets for the crossmember to attach to the frame}and got by with it but I couldnt say I would recommend it to anyone else just because it worked ok for me. Im not sure the setup I had would allow "a lot" of rough rodding around or you might find your engine and trans upside down in the engine bay without the side motor mounts.
might be hard on the transmission case too, it's not really designed to support the weight of the engine
Pickup frame is sorta wide. Need a crossmember to reach over to the other side the reach up and tie to the motor. Lots of those out there.
Found these side motor mounts for your truck on ebay with just a quick search and sevral pics of others all over the net, not sure about the bell housing mounts without looking but I think you may hafta cut that bellhousing xmember out as suggested earlier,thats what I did to the 57 as well. Ecklers,harmons,speedway and others may have them I havent looked. By the way the camaro/nova trans crossmember does fit rite in the frame channel as I remembered, I have a extra xmember out in the garage and layed it between the frame rails on the 55 truck out there just to make sure I remembered correctly.
That mount shown above will eventually crack the frame. Use a tubular crossmember type mount instead.
Where do they crack the frame? does it matter if you only have mild horsepower or would it help to weld em in?
The frame is a channel shape, the mount puts a torque on the frame. A crossmember just puts a vertical load on the frame, not a torque. I'm just telling you about my experience with that type of mount on that type of truck. It's not good.
327 chevy. I found on LMC truck parts this: 34-0305UNIVERSAL FRAME MOUNT KIT But it doesn't have much of a description
Yeah, that's the type I recommend. Should be the same as the TransDapt one. Did you say whether or not your engine has the bolt holes on the sides, for the side mounts? If it's a 58 or newer engine, it should have them. If it's an original 56 engine, it won't.
I used to have a '55 Chevy P.U. with a Muncie 4 speed and considered switchng to an auto. (never did), but wondered if taking out the original trans crossmember would compromise the ridgidity of the frame....Anyone?
Just wondered because I've heard if you change to IRS, maintaining frame rigidity is even more important.
This mount will work but will require boxing of the frame approx 9 inches in each direction of centerline of mount. I would also recommend gusseting the ends of the 90 degree w/the two holes. As long as the front cross member (radiator and front sheet metal support) has not been altered a cross pc under oil pan will not be needed, it would put your worry to rest if you did incorporate it. If I chose to use the full cross member I would not use these mounts and fab my own, or use #5 & #6 as Jim Forbes (Squirrel) above posted along with #8 for the trans.