I can't say it would be for everyone but as for me its my money my car and my likes.
Just wanted to say if you want it do it I was told by a shop 700 for twin pipes, well I don't grow the money like Tim, but I do have my understanding of how to get things done my way.
If its not to someone's liking to bad, I bought a box of thirteen 90's from JEGS and two 10 ft pipes 2 inch and I made my own.
So far no mufflers as it sounds good but if I think later it needs them, I won't have a problem getting them on.
I split my own manifold by cutting the heat riser out ( not much need for them in AZ) and welded a concave peace of steel that blocks the front three.
If that wrong sorry it works for me.
I get a lot of help from my Truck and car buddy's on this forum, passing the time with them or talking shop, most can give you an idea or tell you Hey ! did that and it did or didn't work.
I have built cars for years and I love to play, as for making money with these old Plymouth or Dodge Truck, really don't think that will happen but when and if I get this project done it will be mine.
I am saying all this to say if you feel like you want twins or 12 volt or an Alt, its yours.
Ask you will get a lot of info and we all mean well but its your project just do it.
Seabee Can Do Have Done