hey joe that should be good that should be great like i said i did alot of research before i started cutting holes and it was not easy at all to get someone to give you a dimension but,on straight bottem boat this seems to be a good number,because if you go to high you will not get enough prop bite to lift the bow,stepped bottom boats create there own lift so on those boat the x dimension is alot higher,and dont need as much positive trim to get the nose up

Hey if Bob Teague says between 4 & 5" then thats what it gonna be!

It depends on the boat, not all boats automatically do better with a higher X dimension. The higher you go, the more leverage you lose to lift the bow. The boat stays wetter and my not do as well.

put in in the way it is, and see how it runs, and then if you need to shorten it go with a shorty lower unit. My old 311 with 502's had B1's and runs like a dream. insptech now owns it and has had trouble free fun with it.

Spacers are alot cheaper than the shorties, I think that 4 3/4" is not to crazy, but if it is, the spacers will get me deep enough. I like tinkering anyway...Do you know what the prop shaft hight was with the shorties on that 311? How did it handle?

Thanks Joe

Here’s an odd thing I forgot to mention.
I have the offshore engine mounts. The way things were with the merc trans, the bottom of the motor plate rested right on top of one of the smaller strengthening stingers running under the engine.
With the new set-up, I moved the engine centerline up ˝ inch so I figured there would be space between the plate and the stringer……………nope.
After spending 2 hours aligning each engine, both engine mounts ended up right back down on the stringer (4 inches rearward from where it was before).
The angle of the engine in my particular boat was different. Placing the front of the engine lower than the rear (when compared to how it was with the TRS and merc trans).

Everything was aligned properly, the bravo alignment tool slid in and out with ease. The drives slid right in without a problem, and then right back out after 18.6 hours of trouble free use.

I’d definitely move your crank centerline up.
Good luck!
DS

Well Zanie...you are correct! I did some more measuring last night and found exactly that! The further back you go the deeper the engine gets. But I have another issue. The further back you go the shallower the upper deck hatch opening gets too. My offshore mount will no longer fit at the bottom either. So I have to go the Bravo mount. I see that Mike (offthefront) has them in his. I have worked on lots of HP boats with them...I like them for their ease of adjustment and I can get my engines on the work stand in 45 minutes. Go over and check out the rotton transom thread. I am going to redesign that whole front bulk head to be a more strucural part of the boat wich in turn will tie the stringers together better than they were before. This way I will feel better about loosing the offshore mounts.

Joe