FINALLY; it runs with some authortity!!!!
Was on the turbo forum and read this and thought of you Bill:
http://www.theturboforums.com/threads/362503-Another-blow-thru-carb-question-Help!
Was talking to friend last weekend who has 318 twin turbo and due to his cheap carb hat he was having similar problems than you and was messing with his vent extension at different lengths and his ran best with just the rear extension and no front !!!
Thanks for the link and for thinking about me. There's not much satisfaction in learning that we are not alone with these tuning problems. All that does is remind us that there are people a LOT smarter than we are who need help, too, when tuning one of these blow-thru projects relative to mixture issues under boost.
We have an uphill battle, for sure, but it's still easier than trying to make any real horsepressure, normally aspirated, given the problems this /6 cylinder head has.
Somebody on another thread suggested that what we need is an Edelbrock head for this engine,
The fact is, unless you design a 4-valve head, there's not room for any reasonably-sized valves due to the small bore sizes this engine has.
I don't believe that ANY 2-valve head, regardless of its material, or design, will ever flow enough air to make two hp/cu.in. on this 225 block, normally-aspirated. That's just my opinion, and the reason that I would not spend two cents trying to get performance out of a normally-aspirated 225.
They sealed the fate of this engine in that regard at the factory when they put 3.4" pistons in it.
Hairdryers can change all that... It ain't easy, but it IS do-able...