When I built mine, the RV-7 and 7A were designed to use the TG-10 box. I imagine one could use any of the 3 as desired.
In my opinion, the box is less important than the selection of exhaust manifold and its related heat muff. As a result of my own informal survey, I believe there are performance differences between the vertical induction manifolds and the horizontal manifolds with the horizontal manifold heat muff being less effective. It is simply a matter of available surface area. The exhaust manifold for the IO-360-M1B available circa 2010 for a 7A (mine) has limited surface area available for the muff. It is on one cylinder only (#1) vs after the collector or encompassing 2 ex pipes or surrounding a muffler on other units. All of the alternates provide more surface area and/or more exhaust mass flow vs only one cylinders pipe.
My memory of VAF posts says that there have been changes to the M1B manifold/heat muff design since I built but I am not positive on that.
RV-7A: Flying since April 15, 2012. 750hrs
YIO-360-M1B, mags, CS, GRT EX and WS H1s & A/P, Navworx
My RV Construction Page
Last edited by rzbill : 03-24-2017 at 10:52 AM.