Put the 6's on in the same location. if they are too high its easy to space down. i have gimbals and fresh wet 6's sitting in my shop of you need them

I’ll have a pair of 1” ssm 6 spacers available soon

Thanks for all of the feedback. I am not mechanically inclined at all. I have a VERY vague understanding of this stuff and I am trying to get educated on what I can and cannot do. Also what I should and should not do. We are arlready WAY past what I intended and I don't want to get to much further down the rabbit hole but I have an opportunity to buy some #6 drives at a very reasonable cost. I had never planned on changing the drives as I don't want to spend the money to do so but I may be able to do some horse trading that makes this a possibility and I think an old school 36 with 6's would be kind of bad ass.

I looked at switching to #5's with boxes but with our basic calculations we were not going to gain anything. The angle of the shaft with the extension boxes was going to be too steep to get where we wanted to be. We are a little way away from doing anything, but we have not cut the transom for the drives yet. We have the exhaust holes cut and the new hatch made for the current engine height so it would be a ton more work to change it again............

Thanks again for all of the comments. I really appreciate your time and education.

Those are early #3's just changing to the crescent lower would bring them up a little, I would think #5's with neutral boxes or a 1 up would work fine, what kind of HP are you installing ?

Crescent and non are the same length

10-4 how much shorter are the 5's vs the #3's.....3 - 4 inches ?

the easy way of going from a number 3 to a number 6 and keeping the same engine height is to put the number 3 drill jig on the transom mark the crank center line and set the number 6 jig over the marks and see what needs to be filled in and go from there. As far as measurements the number 6 drive is about 6 3/8 of an inch shorter and the motor is about 1 3/4 of an inch forward of the number 3 set up. so if your drives are 5 to 6 inches deep than the number 6 set up should be fine I like to start with the drives at least an 1 1/2 above the bottom with a number 6. As was stated you can always go down but never up again. If you have any other questions feel free to call Regards Dan 949-646-9778

I told you Dan would have you covered.
RG.

Thanks Rick. Have done one or two conversions over the years. If you need to borrow the jigs I do lone them out no problem. Regards Dan

Wow you guys are awesome. Once I get up to the boat i will go and look at where everything is and see if this is even feasible.....then I make a deal on the hardware. If it looks to go that far i will be giving you a call Dan. Again I really appreciate the information. It's nice to get real information not just bs from people that have no clue and want to argue.

One final question do you think this is a good idea for this hull or not? Other options or just run what I got.

Motors dyno at about 750 hp and 800 ft lbs per side. NA 653 Donovans.