Thanks for replying. There isn't a way to put a header on - the engine sits under a so-called "dog house" that just fits, and the restoration would be messed up if I changed it. Besides, the Intake/Exhaust manifold is a very nice copper structure...
Most boat guys are very concerned with authenticity for the boat show circuit; I just want my boat to run at its best. I think you hot rodders are the guys who understand this best. I hope I can find someone who's had experience with the Chrysler L-head.
Thanks, Grant in VT