Floor on Fiberform

[Rranger]

I am in the process of building my floor and engine hatch over my engine compartment on a 1976 21 Fiberform with a flying bridge. My new engine is a higher profile than the last one. Which means I either raise the whole floor accordingly or build a doghouse around the engine. Can anyone out there give me a measurement of floor to top of gunnel at the rear and directly behind the cabin on their boat. Is there a standard depth or "safe" depth it should be? My boat also has railings I could raise to compensate for a raised floor.
I'm looking at a flat floor with a 15 inch depth from top of gunnel to the floor And I raise the railings or a 24 inch depth with a lower floor and doghouse. Any ideas out there? Thank you.

 

[DeepBlue2010]

What is the difference in hieght between the two engines and where the difference coming from (Intake manifold, Carb, etc)?

Did you upgrade the block? Post some pictures so we can see what you see.

 

[Rranger]

I appreciate the response. I found a boat in the small town I live in to measure. Thanks.