Simple looking job took me a long time to make. Maybe 4 hours. Plans only called for three attach points to firewall but six looked better to me so I used all 6 predrilled nutplate holes in the powder coated angles. Some nutplate holes matched up with existing firewall rivets so those rivets were drilled out. Temporarily put the firewall recess back on so appropriate AN4 bolt holes could be drilled through that as well as the firewall seeing as they overlap in that area. Keep your mind on full. I drilled one nutplate mounting hole through the firewall before I realized none get drilled through firewall because all nutplates attach to the angle with dimples on back side so it lays flush to firewall. Duh. Plans called for lightening holes in the tie down bar on top ( I agree) and in the black body (I disagree). I've seen some sites that show a swollen battery case filling the case lightening holes making it extremely difficult to remove battery. I'll leave mine flush and absorb the weight penalty. Spacer tubes between the tie down aluminum bar and the mounting brackets called for .75 long in the plans. Test fitting mine first showed I need .90 so thats what I made. Its all good.
Drill out required rivets in firewall to use for AN4 bolts andor nutplate mounting holes.
3/4 lightening holes in tie down bar plus spacers underneath.
