TOPIC: Transom Clamp question

Can someone tell me the maximum allowable gap (inches) when the motor transom clamps are completely open on a 1950s Merc. Replacing transom on my boat and want to ensure I am not fabricating it too thick. Looking at a final thickness of slightly over the original 1.75"
Thank you.

I've gone 1/4 inch larger with no problems. How wide does your bracket open? I know I've had mine on a rough cut 2X4 with no problems. I've seen some real hack jobs on transoms before. I've seen double thickness of original on one. He just tacked another one on over the rotten one. He had a six hp Johnson on. Good thing it was not a 20 because it was kinda rickety. I'd been scared to go in it myself. Other than the bracket clamp I always use stainless steel bolts and seal them. Never had a problem. Pictures might help.

I guess that is my question Robert.
I don't actually have the motor yet. I need to know what the max gap on the brackets (clamps) are on the 50's Merc. I plan on purchasing and putting one on once the resto is complete.

Oh I see, I'm not sure what the will open to. I never measured it. Maybe I'll have a look tomorrow.

Cawrsfm,
If you stay at 2" or less all the '50s Mercs will fit fine including the Mark 20, 25, 30, 55, & 75.
The 1959 Mark 58A & 78A can fit on a 2.5" transom.
After 4-6 cyl models after 1959 fit up to 2.5" thick transoms.
Thom

and,...depending on your location I can probably help you locate whatever '50s model Merc you desire.

Thanks Thom.
I am looking at a 58A so I am very relieved that my thicker transom will accomodate. Thanks again.