Can you run a Chevy 350 cam in a Chevy 305 with stock 305 heads?

Yes, but running a 350 cam with 305 heads is not effective,you need to run 350 heads as well. In order to benefit from a 350 cam you need something to flow that extra fuel and air, so using 350 heads along side of the 350 cam will be the cheapest and best choice. HAVE FUN!! A 350 head can physically bolt onto a 305 block. However, 350 heads can have the valves extend into the cylinder and contact the cylinder wall (even with the smaller 305 cam). The 350 cam in the 305 with stock heads will work. You wont want to use 350 heads you will lose compression due to the largers combustion chambers.