Hello 300 Fans - Phil Irish here. When I made my "Kit Kar 300" from my 69 Newport coupe, I stumbled on a set of these manifolds to add to my TNT rebuild of the 440. Having done the entire engine in one effort, it is difficult to say how much they add, but the whole engine response is noticeably better. I do know Carl K. of early 300 racing fame, believed good exhaust manifolds and pipes were worth 50 HP on the 392 cu in engine. They are impressive to see on the engine and I've never failed to get questions about them when the person looking had any engine knowledge at all. I do not have the part numbers but will say I've never seen them offered at a swap meet, or on ebay. I suspect finding a complete TNT engine would be the only way to get a set. I only know of one of those - and I don't think it is for sale. Good luck in your search ! All the Best 300ing, Phil - snowy 38F outside Memphis . [Non-text portions of this message have been removed] To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Chrysler300/ <*> To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/