Shower drain distance from toilet

I am remodeling my master bathroom in which the existing shower stall drains (2" line) into toilet drain and then into main stack. The distance from shower drain to toilet is approx. 3'-6".

My plan is to move shower over in which my 2" shower drain location distance to toilet would now be approx. 6'.

Since this is a wet trap does the additional 3' matter?

One of the pros will correct me if I'm wrong, but I think on that size pipe, the limit is 5'. Where exactly is the vent now for those two fixtures? If at the toilet, I'd think flushing it would siphon out the shower trap.

The house was built in '76 and the line from the shower to the toilet is piped into horizontal main drain on 2nd floor for 2 bathrooms. From the toilet to vertical main stack is approx. 5'.