OK, I looked at the DIY sticky and I even searched for "glow plug replacement" but I still have a couple of questions.

I'm putting the new pencil style glow plugs into a 77 240D. Do I need to ream the glow plug holes somehow? There is a little loose carbon laying on the threads now that I've pulled the old ones out, and I figured I would just crank the engine over to blow that out before I put the new ones in. Also, what gauge of wire should I use to connect them? Looks like 8 is what is coming from the old relay plug, is that right?

Also, I have a push button switch and relay and I am thinking of converting the new plugs to manual control, but can I use the old relay if I decide to try that, or do the different plugs need a different relay? I noticed that the new fuse is 80 amp as opposed to the 50 amp that the old plugs used.

I already know to leave the ground strap off of the front plug when I get that far.

Thanks!

__________________
1976 Mercedes 240D, unknown mileage
1992 Dodge/Cummins 4WD, 284k