37 AT & 380 tabs
 

I ran across this diagram in a stack of papers on my desk, so just going to upload it here for others if needed.

Quite a few years ago, I upgraded my 37AT from 280 K-planes to 380 K-planes. If you are going to do so, it's recommended that you "lop the ears" off of them so you don't have conflict/contact with the drives. I did actually have this happen once due to my own negligence. I had tabs down after coming off plane in a shallow area, and then trimmed my drives up a bit too far, and turned the wheel. Fortunately, I had my drives in reverse at the time, and the trailing edge of my prop nicked the inside of the tab; so no damage to the prop, just a quarter-sized nick out of the tab.

These measurements are taken off of one of the boats that Pat installed 380s on originally. This is the starboard tab, so just reverse for the port side tab.
I had a machine shop cut mine down on a proper bandsaw, and then repainted with gloss black epoxy paint to match the rest of the Phantom Black Mercury parts on the transom.

Wow...you actually USED the tabs? Lol. I've only used them twice in 4 summers...and that was in some BIG stuff. I love that I don't even have to touch them.

Yes, I used my tabs all the time, but only to get on plane. After that, they go to neutral. Pat taught me a long while back on how to level the boat in side-side/quartering seas using the drives, not the tabs, and that's my preferred method for most conditions.

But this particular time that I used the tabs, I knew we were coming off plane into really shallow water. It was only 3' deep or so, and we could see the sandy bottom (in the Keys). I had dropped the tabs while on plane at speed, and pulled the throttles back to "coast in", in neutral. Dropping the tabs keeps the transom from dropping down quickly; so the boat settles just like it raises; flat.

......my 380's have not been cut....

You have extension boxes, correct?

ITS = 8" set back

Not really a concern then; as the drives are way past the tabs on your Cigarette.

The majority of the 37ATs are built with the drives direct on the transom, as that's the way Harry Schoell designed and patented the bottom...
...as such that the drives on the transom puts the prop shafts, transom edge, and step on the same level plane.

Pat has but extension boxes and ITS on some boats, but that all requires raised X-dimensions via various methods to match what I describe above. But the boat doesn't need setback to perform.

ITS 7 inches of set back

Should I be running my tabs at neutral? I usually have them all the way up...don't even drop them when coming on plane. Boat rolls over really nicely at 2800-3000 rpm...

These boat's run pretty flat with no tab , Is there any real use for these larger tab's ?