The 4 stroke motors are heavier than the 2 stroke motors. On the STM I had to move my firewall aft 7/8", don't see any reasons why this is harmful.
You will still need to add weight to the nose once completed. Telemasters have a long fuselage and any strenghting you add, or in my case tail mounted
servos as well, lead in the nose will be required.

I like electrics too but a 4T in a telemaster is a nice match.

-Brad