Johan Even tho you have multiple questions, they are mostly related. The snorkle is used to cause a "ram effect" to the air cleaner. The early style was a round tube and the later style is rectangular. The new style has a fitting for a warm up tube from the exhaust manifold and some other fittings for vacume tubes. This same air input tube also has a fexible air intake hose on the newest models. The hose is to have fresh (cool) air from the out side to the carb. It was found the fresh air was a cheap way of getting better hp. At first this was only found on the hot hp cars. Today this is also found on a GEO. Starting in 1967 MoPar started offering a dual snorkle air cleaner housing. The dual snorkle was only on the TNT/Mag engines (and yes one could get a dual snorkled 440 with 375 hp Imperial). The rectangle styled air cleaner's have the "pie pan" cover. The clutch fan assy is also to keep from "robbing" hp. It takes more power to have a direct drive fan assy. The fan shourld makes for a more cooler running engine. I've got to go to work. I'm sure that others can fill in the blanks from my reply to help you with your questions. Rodger & Gabby 47 De Soto Custom 63 Le Baron with round dual snorkle air cleaner 66 Le Baron " " " " " "