Fuel system Upgrade for Blata 2.5

Ok guys, if i choose to go into the open 2.5 class, I have a very good mechanic that knows his 2 stroke engine. He is the "Giannini" of LA. I was skeptical of his work, since all he has are cags but now i'm a believer. LAstnite at my ride spot, i rode one of his cags that he worked on the internals himself and it pulled away from the 50 cc dirtbikes. I don't want to throw out numbers on speed because i was not radar tested, but from the ride, it must have gone 45 + , 40 + easily i know for sure. Well anyways, I've been riding with this guy since the very begininning when i got my cags. I met him at the tracks, and now i'm going to trust him with my engine. My blata 2.5 engine. He told me that i can upgrade to a bigger dellorto carb, biggest up to 17.5 mm, and then he will match the head and everything else, ports, blah blah blah..internal stuff for free for me. The only thing i have to give in return is tell people when i win, who made my bike. He already made a open class cag that raced at Amago and won first place w/ Eric riding it a few weeks ago. He's not charging me, because he wants me to ride for him at the races. My question is...will the polini parts fit onto the blata 2.5....like the inlet manifold most importantly. And whats the jetting i should get for 17.5 mm carb and 15mm carb. I may go with the 15mm to save some cash... i would like some of you feed back guys who ride Euro bikes