Transom thickness

"ok i got my tansom sanded and

"ok i got my tansom sanded and ready to start fitting the new wood. origonaly this boat had twin omc 3 liters. i am repowering to a single small block chevy with mercruiser outdrive. i was wondering how thick to make the transom, and if i should put the stringers in the origonal places. i dont have my doner boat yet, and need to know how far apart they need to be. also how high from the bottom of the boat should the top of the stringer be? i am trying to eliminate line up problems when i install the drivetrain.
thanks, mike"

"Ayuh,.... Lotta Questions the

"Ayuh,.... Lotta Questions there Mike,...

The transom Thickness for Mercruisers is 2",... I think the (+) or (-) is 1/8"...
It has to be Flat,+ Parallel, which is probably More important than the over all Thickness...

The Stringers are part of the Hull,+ must be treated as so...
If that can be made to fit the motor,... That's Great...
Otherwise, building the Motor Mounts will just have to be adapted...

Some of the #s you ask about are,...
The Motor's foreward mounts are 22, 1/2", c to center...
The base of said mounts are 3, 1/2" Below the motor's crankshaft centerline...
It's 19, 15/16" from the Foreward motor mount centers to the Aft motor mount centers...

Crankshaft Centerline is determined by Where you cut the hole in the transom,...
So,...
The rest of your questions about stringer placement,+ sizes will have to be Fit around that...

To establish That Point,...
The Propshaft Center is 21, 13/16" below the Crankshaft Center....

I usually use a cut-out piece of the Donor boat to do that operation...
If you get the C/shaft, P/shaft centerlines in at the right height,+ Plumb Square to the Keel Line,....

You'll be very Happy with the results of your Labors....

Good Luck...."