True 75hp? OMC 49ci -81

just started to take a closer look at the Engine I brought home last week, the label at the bracket says E75ERCIM wich makes it an 75hp from -81.

Is there a way to make sure it is a 75hp? other than to take the head off...
I tried to take a peek inside the top cylinder but could not see any chamfer over the exhaust port, only had a tiny mirror and an LED so I might be mistaken.

Got some numbers on different stuff if it might help.

Block: (just behind the ignition parts) 385031

head: (Just by the upper attachment Point for the ignition bracket) F 319335

Core plug (under lifting Eye) 70673D B04846

Flapper type choke carbs marked: (body) 326951 (float bowl) 313355

Got a bad gut feeling about this, the powerhead seems untouched (still original paint on all screw heads) but ignition and fuel seems to be removed and attached and so seems the bolts that holds the powerhead...

My 81 doesn't have flapper style choke then again maybe mine were changed, it's possible that the carbs were removed to changed the reeds, only one way to find out, as for all those parts # I will check tomorrow after noon if I go where I store my boat.

I also have an 82 I can check, carbs should have a tag on them.

Thanks for the help Mike!
Spent a couple of hours on the Internet last night and found out that 70673D is the model code for a 70hp from -76. Guess my gut feeling was right. If only I had seen this when I picked it up...

No biggy Per, I never torn apart a 70 HP but I'm sure not much difference between the 70 and the 75, carbs are the same maybe not the jetting but the carbs are the same, as for all those serial #s not much matches except the carb bowls on my 82 and has the butterfly choke plates. It's very possible that everything has been changed on these motors, you are looking at 30 plus years but what I can tell you is that my 81 has a grey painted block and my 82 has a black painted block, hope this helps.