Firewall pass-through sizing?

Hi guys,

I'm about to purchase some of the popular stainless pass-throughs for firewall electrical. What's everyone's experience with the sizing? Seems like there's 1/2", 3/4" and 1" I.D.s. My electrical system will be fairly simple, but with full engine monitoring.

The plan is for two-pass-throughs up high, and a third less glamorous hole near the battery box, which will be handled with a snap bushing, stainless cover plate and lots of Fire Barrier sealant.

I used two 1" pass thrus, one on each side and had plenty of room for all my wiring. I also put a few spare wires thru in case I need them in the future.

My layout is about the same. I have a 3/4" fitting on the pilot's side and a 1" fitting on the right side that handles all of the EIS sensor wires.

Chris

Thanks for the input!!