Ok!! I just have to know

I am looking for a show and a good driver only. No hot rod.:stop:
I have a offy intake for my little/6 170.
It looks like the exhaust is the big problem here.:-k
I have learned there is no difference in the 225 and 170/ exhaust.
So! The original pipe that connects to my exhaust from factory looks small.
Or is it the biggest pipe I can connect to the manifold.????:sad4:
Remember I just want a good driver and show:-D so what can be dun to use the 170/ standard trans, I have a very light foot, so how bad will the
390 Holley with out headers. Can this be accomplished.

I have sat here wondering if I should even ask such a question.:help:
I do not have the 390 yet, so I am looking for some suggestions.
Victoria don't need more power for my use, just a good look under the hood.
I will keep the three on the tree and just up grade to electronic ignition.
new dist and all mopar parts.

Am I just dreaming :help::salute: