I JUST SOLD MY 2.5 MERC OFF MY 98 MACH 22. I WAS PLANNING ON GETTING A 300X PUT ON IT. IT WILL RUN ABOUT $18,00O INSTALLED. MOST OF THE POSTS I HAVE SEEN TELL A STORY OF AROUND 88 MPH WITH THE OLD 300 PROMAX. THE BOAT RAN 84 WITH THE 300 PRO MAX IN HOT BOAT. THEY SAY IT WILL DO BETWEEN 92-95MPH WITH THE 300X. I CAN PICK UP A USED 300 PROMAX FOR ABOUT $11,000. NOT SURE IF I WANT TO SPEND THE EXTRA $7000 ON THE 300X UNLESS I SEE A BIG DIFFERENCE IN PERFORMANCE. I KNOW THE 300X REVS ABOUT 600 RPM HIGHER THAN THE PROMAX. ANYONE HAVE EXPERIENCE WITH THE MACH22 WITH EITHER MOTORS?? I'M SURE MANY WITH THE PROMAX AND FEW WITH THE 300X. SINCE I ALREADY KNOW TOBTEK WILL RESPOND TO THIS POST. WHAT IS DAVE TELLING YOU YOUR NEW BOAT WILL DO TOP END.