No tranny mount on my TH400? 70' c10

[Mrturner1]

I'm in the middle of an engine rebuild and currently have the engine out but transmission is still in, sitting on a block of wood and still has the driveline hooked up. When I pulled the motor I was very surprised to see that there is no transmission mount. It's bolted to the motor, and then hooked up to the driveline. I always wondered why it felt weird when I would jump on the gas at higher RPM's, and I think this is the issue. Truck is a 1970 C10, with a th400 and 350 SBC.

Should there be a trans mount?

And could this be an issue IF the truck was previously a manual transmission?