Beats me what Brook (a salesman at Callies) has to do with this, unless he is the one who told you about the 18.00 -1 compression.
You sorta left out some ital inormation for anyone to figure your static compression ratio. What is the dome or dish cc of your piston? and what is all of this posting in mm of all the dimensions? We are in the US of America.
If your engine builder is making that thing to run and live on pump gas with 18.00 -1 compression he knows far more than I, or anyone else on this forum or for that matter any professional engine builder I know.
It might be interesting to figure your compression if there was information to do it with. You gave everything except for the piston cc. I do refuse to take the time to convert anything from mm though. NHRA Pro Stocks do not have that much compression. Comp eliminator engines don't, and I know of no cup or NASCAR engines that do.
And you are saying that this is on Pump Gas?
Ed