Small port heads, big port intake. How bad?

DionR said
I've got a 71 Dart with a 318 and an dual plane M-1 intake. Popped a vc off tonight and confirmed that it has the stock 318 heads.

So, unless I am mistaken about the M-1 intake, I have a large port intake breathing into small port heads. I've always heard that was a bad combination, but how bad?

Trying to improve the mpg on this thing, got 14 last time I checked. Thinking I should swap a 2bbl intake and fix the problem. Any thoughts?

Thanks!
Click to expand...

If you need a stock 2 barrel intake I've got one I could part with. You could probably even talk me out of a 2v carb, worked before I pulled it, although of course it could probably use a refresh.