I was able to get a killer deal on a Makita power head on Black Friday ($99), but already owned a bunch of Echo PAS attachments. So... I hope everyone can please forgive me; at least it's not red and blue right!?!
In case anyone is wondering, the RPMs matched perfect, but no this is not a normal thing to do. Required welding and shimming out Makita's shaft tube as the Echo clamp assembly is made for a bigger sized tube.
Works like a champ. Best power head I've used and the smoothest my Echo PAS attachments have ever felt, and there are a lot of Echo PAS attachments too:
https://www.echo-usa.com/Products/Pro-Attachment-Series
Did some edging and to my amazement, the blade never bogged down at all. Highly impressed with the way it turned out.