/6 single or dual exhaust?

Dart Dad, kind of overkill on the exhaust. Not much of a point having a single pipe coming off a stock manifold only to go to a Y to two cherry bombs and out the back. IMO it would only be more weight which actually will slow the car down and it will do zip for performance. With a single manifold pipe best to stick with single exhaust. You are not going to get any better sound or performance with duals that way. If you want that sound slants are famous for with mods you gotta do split hedders or 'Dutra Duals'. Ever heard a slant with true duals, (AWESOME)!!! Kind of sounds like a top fuel funny car.

I think you could get some better performance with 2 1/2 all the way from stem to stern with a nice flowmaster or a like muffler. Stay away from that aluminum super six intake. They are nice but are known for the crappy welding and leaks. Post a pic of them hedders. We may be able to figure what they are. With that .050 head you might want to consider hedders. Your going to lose most of that milling with single exhaust. Too bad you could not have had some porting on that head. THAT is where the HP is lost.
Chas.
Lots of good info. First I will get some photos poster a litle later. ( I need my wifes help with that) I am familiar with the Dutras. Here is a question, right now I have the 1 bbl with factory stock. What a dog... However once it warms up it does run smooth. My concern is if I use the stright headers will I need a manual choke? Also on the head, I didnt want to over modify. In my thought picking up the compression without opening up the valves woulds still leave decent MPG. Here is a picture of a highway 61 model that I'm trying to duplicate.