The BME is 6" long, 10 7/16" wide, the DA is 6.5" long, 11.5 wide. I know this because I sorely wanted to rip the BME 100 out of my airplane and slap in a DA for the extra performance. Rather than hack the firewall, I'm waiting for a 110, Keith promises the dimensions will be the same as the previous 100 class engines, the jugs will be wider, but the spark plugs have more angle.