The tranny swap went ok, "truck" tranny turned out to be a car model as far as I can tell, but I'm mystified.

I needed to use my kickdown cable, when I went to remove it I found a 10mm wrench size bolt holding it in place. I assumed the previous "mechanic" had stripped out the standard one and used the little bit larger metric one. I tapped it out for a standard 1/4" and proceeded.

Fast forward a couple of hours, I'm installing the converter cover and the 1/4" bolts won't start. Since there wasn't one on it when I took it out I assumed again that Joe Strong arm had stripped those out too. Grabbed the tap and installed 1/4 bolts. Rolled to the side to put on the shifter U bracket and the 3/8 nut won't start, I tried a couple of other nuts then decided that maybe the threads got mangled and grabbed by 2/8x16 die. It wouldn't start so I didn't force it.

Then the light bulb went off. I went and grabbed an assortment of metric nuts. 10mm thread size went right on!. So it looks like I have a metric TH350

Didn't know they existed. I'm not really worried this trans has been behind a pretty stout 350 in a C10 truck for 2 years without any problems. For what its worth there is a big "L" cast on the top of the bellhousing.

Anyone else run into this? If I ever have to rebuild it are the internals differenct too? Thanks Patrick

On my TH350 the bolts that hold the trans mount on, the bolt for the speedo "bullit" and the kickdown hold down were all metric. I thought they were all like that but dont know for sure.

I believe the TH350C is metric. Don't worry about it.

just the bolts, internals are the same

Thanks for the replys, it is not a TH350C, no provisions for the lock up wiring, I'd never ran into a metric one before. This is my 4th th350 all the others had "inche" bolts and nuts.