Welcome to the forum!
As to where to post - there's a few places that could be used:
If you're just posting a few questions about a specific engine, there's a Help section 4-5 sections down with the first sub-forum called "Specific Engine Help".
If you're interested in posting several updates on your build, along with your questions, then using the "Engines" section, probably the "From Kits/Castings" would be appropriate. Unless its not from castings, then maybe "From Plans" would be a better choice.
And welcome!
Kim