Header recommendation, 1968 Dodge Dart, 340 4speed

If you have manual steering (didn't read all the posts) I would not buy any other than Hooker 5204. A stock 318 LOVES 1.75 headers. Skip the 1.625 and stepped header crap unless you are going to do many pulls on the dyno and test your brains out for little (if any) gain.

Now, if you were running 10.0:1 or more compression, had a 3.7 gear (or lower) I would tell you to look for some Hooker 5303,

They are 1.875 diameter but they are no longer made. I buy every set I can find (and I only have one set now and use them.

If you look very carefully at a recent comic book test where they dyno a small block (can't remember the CID but seems like it was a "junkyard" 3600 and they said they tested with hooker 1.75 headers. They evidently can't read simple measuring tools as I have that exact same set and they are 1.875. The thing made bitching low end torque.

Do your research before you buy.