Okay...

Let's mark up and drill the firewall for the Hyde mount - Mike designed this plane around the Hyde AR-80 mount and strongly suggests "no substitutes". But any mount can be installed as long as you can fit it within the 6 3/8" between the firewall to spinner back plate. I learned this the hard way when on my first VF3 build I tried to install the high dollar Hyde ARIA-S mount which is about 6 5/8", yea that won't work...

The first photo is of the firewall from the plans indicating the proper position for the mount's center line. I created a template from the actual mount, taped it to the firewall and drill for 6/32 blind nuts. Just double check everything before drilling. There is critical alignment between the engine mounting position, cowl, and chin, there is a lot going on here so just take your time. When we mount the cowling you will see how that all fits together.

Don't worry if you mess up the position it's easy enough to plug the bad holes with dowels and epoxy and re drill, so don't stress to much.

Once done tap in 6/32 blind mounting nuts - I like using the T-nuts you can get from Lowes or Home Depot - they have a larger mounting flange than the usual hobby shop variety.