318 MPG and HP

Hello, I have a 68 dart 4door with the original 318 that has the orginal flat top pistons, if i swap the original heads with a pair of 89 360 heads,(i have them) approx how much would i have to mill them to keep MY cr the same, or even bring it up? These heads are about 70ccs. I may even concider magnum heads.. Would the 270H comp cam be ok? ( I have it)or is there a better choice.

I would like to install a TQ carb,(i have one) and 360 manifolds or headers. I am running a 904 and have an A500 to swap it with. I have 3;23 gears now and i think these will be ok for my use.

Oh do you know if i can use Dakota shorty headers or block hugger headers on a dart?

I am building for mostly MPG what are your opinions? And NO i do NOT want to drive an econo box, I love driving my dart everyday.. The ole girl even gets a once in a while.. whens the last time you gave a thumbs up to an econo box..

Thanks Don
Author: Dakota_Don