Gear Tower Mod parts list

I plan on doing the gear tower mod on my -8. The fuselage will be here soon. Can anyone recommend a list of parts I should order for this mod? For example the size of hardware, nut plates, quantity, and where you would recommend purchasing the hardware etc. Thanks in advance.

The RV-8 gear tower "mod" is nothing more than removing the material between the top and bottom lightening holes. I simply made a large oval by drawing straight lines between the top and bottom holes. Make sure you blend / debur / smooth the areas where you cut the material out to avoid any stress risers. Some folks leave the area open, I chose to install a 0.030" thick cover plate, with 3/4" over lap over my opening by using #8 screws and nut plates spaced at about 2" or so to add some structural integrity back to the web area. Ease of access is greatly improved and it looks tidy. The cover panels can also provide a place to mount a fire ext or canopy breaker.

I just did them on mine.

I ordered the parts from Aircraft Spruce, a 2x2 sheet of alclad 2024T3 (I went with 0.050 thick), and a package of 50 K1000-08 nutplates and 50 screws (8-32 8R8 screws). The kit comes with a bunch of nutplates and screws already, so you may be able to get by using those first and reordering later.

I didn't do the mod until about 2 months into it, after I already had things together, then apart, then together again, just before putting on the front side skins. I'd recommend waiting just a little after the kit shows up in case you have anything else you want to order from Spruce, you can bundle it into the same shipment. If you just order them from Vans and have them ship it in the crate that may make sense as well.

I've seen a couple of different methods for the tower mod. Option A is to open up the web between the existing lightening holes and fab up an oval cover to go over them. Option B - which I did - is to cut the tower web into three sections, with the center part becoming the removable cover.

For Option B, I opened up the -4 rivet holes on the perimeter, then added four screw holes at the upper and lower edge of each cover plate. In retrospect, three screws probably would have been better - it's crowded to get four screws in there, and I had to use single-side nutplates in eight places.

Anyway, the stuff required for this mod is minimal. I used #8 flush screws and nutplates, 29 for each tower; I just went ahead and ordered 75 of each because it never hurts to have spares and I'm OCD enough that odd numbers bother me. The only other thing needed was some .040 sheet to fab the doublers; I had enough material in my various trim bundle piles to make this without needing to order anything.

Here's a photo of the finished gear towers:


And pertinent entries from my build log:
http://rv.squawk1200.net/2015/05/04/priming-right-gear-tower-modification/
http://rv.squawk1200.net/2015/05/06/left-gear-tower-modification-and-match-drilling/
http://rv.squawk1200.net/2015/05/07/countersinking-and-dimpling-towers/
http://rv.squawk1200.net/2015/05/08/drilled-some-nutplate-holes/

This is perfect... Exactly what I was looking for, thanks everyone!