Since I haven't run one up yet, I don't know if vibrations would be an issue. What servos are those running this engine are you using?

I run standard size, analog, nylon gear on all my gas engines.

So Futaba 3004 should be fine for this?

Yes, that is my most common throttle servo on gas models. I don't remember one ever failing.
I always use a name brand servo with a ball bearing at the top (which the 3004 futaba is).

Great, I can use the 645MG elsewhere that is more fit for it's use. That gives me a spare one for the parts box. I still need mini or micros for the doors. 17 servos and counting for the B-25!