can someone tell me a local retailer that sells theses things? i've tried home depot and sears harware where i work but they only have generic hose clamps, do i need to go to a plumbing supply store or order these?

 

Marine supply places carry them. Some independant parts/speeds shops carry them.

 

Truck supply stores are ussually a hot ticket to get them cheap, 2-3" ers are ussually around 2-3 bucks a pop which is WAY less than most places try to rake you for. Also you can ussually get V band clamps for exhaust parts at truck supply houses. There's no mainstream chain type store that will carry them, they're pretty specialized.