Ok the more I read on here the more nervous I get. I am putting a 18hp sd on a 1648 weldbuilt (I said alweld before but I have a weldbuilt). Someone mentioned that the transom angle should be around 20 degrees.....ok my question is what if my transom isn't on a 20 degree angle?? Do you just shiv it out or do you have to dismantle your transom and get it perfect how much of a difference is it going to make if its not. And Im posting a "Microsoft Paint" picture (excuse the poor artwork didnt have time to do a photoshop one) I need to know what the measurement should be that I have pointed out in the picture so I will know how much to build my transom up because right now the bottom of the gear box hangs below the bottom of the boat.

It didnt post the pic let me try again

ok for some reason the pic wont post but lets just say my transon is on a 20 degree angle how far should the bottom of my gear box be from the bottom of my boat

Well I think that a short transoms motor needs a 16 in transoms an a tall transom motor needs a 20 or 21 inch transom I think that's right . As far as the angle you can just shim it to get it to the correct angle

ok thanks for the advice.....what about the distance between the bottom of the gear box and the bottom of the boat??

About 2" above the bottom

Thanks for the advice guys