Just got a new to me flat 8 for my 49 f1, anyone know of any good motors mounts I can use ?

 

Flathead motor mounts for F1 pickups are available everywhere old truck parts are sold.

https://www.dennis-carpenter.com/tru...otor-mount-kit

 

I've read this a few times and it's possible Wayne answered your question.
The other answer might be: unlike the motor mount struts that bolt to the block of your I6, the V8 motor mounts are part of the casting of your water pumps. The ears of the V8 water pumps sit right on the biscuit cushion that Wayne is referring to. The crossmember is the same for both engines.