I am building a couple of motor mounts, for an Avid MKIV, based on what I believe was a Jabiru factory mount for the Avid. There are a few questions I wanted to pose to the community. First, has 5/8 OD .035” wall 4130n shown to be strong enough for the tubing or has there been movement to .049” wall? . Second, does the MKIV require any downward bias on the motor center thrust line (ie. 5 degrees nose down)? Next, is there side angle bias, to correct for any P-factor issues, when using a Jabiru 2200, with a 62” Sensenich prop, on a MKIV with a stock rudder and tail? Last, What points do I use to level the fuselage (level flight) for a reference angle that I use for setting the thrust line? Is raising the tail, until the rear h stab is level, accomplish this? FYI: It will be difficult to unfold the wings right now. Thanks in advance.