Has anyone figured out how to extrapolate the X-dimension from measuring from the bottom of the transom housing along the transom to the top of the notch? Seems like I read a thread about this a while ago. If anyone's got this let me know - mine measured 5 3/8". Thanks.

Kokopelli,
The actual X dimension is the vertical (not along the transom angle) distance between the drive shaft centerline and lowest point on the hull (on our boats, the pad).
On my boat this worked out to a rather high 19 1/4"s. This is why many of us are finding some extra efficiency (lower slip %/higher speed @ rpm) by using a 1" spacer and/or going to a 5 blade propeller.
As you have probably seen, many boats have a much deeper X dimension, and that's why Imco and others are selling all these 1, 2, and 3" short gearcases. In our case, it appears the factory has gone in the opposite direction direction, and on the late model step hulls gone too high with the X dimension. If you have a 2000+ step hull heat with a high X dimension, you definitely want to try a 1" spacer.
I have measured the X dimension on a pre step Heat (1999 back), and it was much deeper at 16 1/2"s, and these boats may (no one locally has done it, so I don't know) benefit from a short gear case.
Regards,
Steve

Koko,
I have a spread sheet somewhere and by the method your using it seems to me that all of the stepped Heats I have measurements for (about 10) they are all at 6-1/2 to 6-5/8 at that reading. I will check to be sure but it sounds as if your already down.
Dave

OK,
I found the spread sheet and the magic number is 6-7/8" which BTW is what I have for your buddy's new boat that used to belong to Rick Young.
I think this is the number where a spacer will do well.
I have some sea level numbers for that boat as well if you are intrested.
Let me know,
Dave

If thats the case I must have one of the few step bottoms with a lower X. What's the easiest way to measure when it is on the trailer?

Yea let me know what the sea level numbers were. He's trying to decide what props to put on it for Powell and Flaming Gorge. Do you know if Rick swapped out the lower - the one that is on there seems to be newer than the upper and also has holes drilled in it for a different drive shower. The lower he has, has the dual water pick-up.

Simply measure from the bottom of the transom housing to the top edge of the notch (lay a small straight edge along the surface of the notch for accuracy)
Just compare it with your buddy Pat's for comparison.
Dave

I have no idea on the lower. Might want to call Rick.

He will want a 22 Bravo for Powell (maybe 24 if he plans on a lot of cruising with a light load) and a supercharger for the Gorge

Sacramento Delta
26 Bravo / 74 degrees/12" chop= 66mph at 4900
26 Bravo / 95 degrees/12" chop= 64mph at 4750