Can anbody tell me if a Weiand 256 blowers come in different nose lengths.Is there any problems with distributor clearance.I'm planing on putting one on a Gen IV 454.I have 502's with 177's on my big boat and run Holley 850's.Does anybody know what dual carb set up to begin with on a 454 mag,stock except for 525sc cam and roller rockers.Any help greatly appreciated.