Hello everyone, latest edition here, hopefully I can help a few of us along our way! But let me pick some brains here, is a TH350 trans a direct fit into a 66 running gear? Thanks in advance, Chris
Hello Chris, Welcome to the forum. A "direct" fit, not requiring modification to the driveshaft, would be rare. BUT, other thing to consider will depend on what is in there now. If you have a standard manual trans now, the bellhousing crossmember will need to be removed, a trans crossmember added, and the driveshaft shortened. DVal
THATS RIGHT DENNIS, I CONVERTED MINE OVER, YANKED THE MANUAL MEMBER OUT WITH AN AIR CHISEL, BOUGHT A AUTO TRANNY CROSSMEMBER FROM EARLY CLASSICS, RUBBER MOUNT FROM CARQUEST, AND IT WAS IN 66 KUSTOM
It started life as a three speed/column shift and somewhere along the road it was changed to a four speed/floor shift. So, shorten the drive shaft, replace crossmember, and is there such a thing as a kit for the kickdown cable to couple it with a single barrel carb?
You will need a vacuum source off the intake manifold for the modulator on the trans. Was that converted to a "Granny" style 4 speed with compound low 1st gear ? And, if so, was the trans hump changed to a "high hump". The column shift 3 speed trucks had a low hump trans cover. The reason I ask is if it is still the low hump, you may need a small amount of clearance at the bottom of the firewall for the bell-housing area of the trans. I've only converted a granny style so I'm not positive on that one. Anyone else know for sure ? The kickdown cable should work out OK with some minor tweaking/fabrication. DVal
Yep. its a granny, and the monkeys cut a hole in the floor so the trans would fit. I put it up on the lift and the hump appears original (modified of course).
The high hump featured a remobable trans cover, held in place by 12 or 16 bolts. The low hump was not removable. Mine had a high hump trans cover installed by a previous owner. The low hump was removed by cutting it out using the high hump trans cover as a template for where the bolt holes needed to be. There is one thing that you need to be aware of if you want to make the conversion to a high hump. There is a flange spot welded into the bottom of the firewall area just in front of where the trans cover mounts. I this was missing from mine and the gap coverd with a hunk of sheet metal held doen with screws. It leaked hot ait and moisture like you can't believe!) This flange is not present on the low hump cabs. So if you find a cab in a wrecking yard that has a high hump, you need to be prepared to take that flange with you. A cordless drill and a NEW quality drill bit will make short work of the spot welds. To install in a low hump cab, trim out the floor to where the low hump meets the firewall. I used rivits and seam sealer on the flange and it works perfect. The better choice would have been to spot weld it back in. DVal
it does have a removable panel so ill just patch the old one where they cut it. thanks again for the info.
ive found a site that says the th350 is the same length as the powerglyde and has the same output shaft, so swapping from a powerglyde to a th350 should be pretty straight fwd. only thing is the shifter. i think youll need a floor mount shifter or swap in a column that is from a 3 speed auto truck or van.
