Cross-over pipe on duals

I will have to look and see if I can put the H pipe close to the manifolds. I do know that I can easily do it closer to the mufflers, with the way this exhaust system is routed.
Not sure how much it will help that far back, but I do see stock exhaust systems with a crossover before the muffs. What can it hurt? I don't think much.
I have a MP quick advance dizzy with the design2drive HEI module conversion on it, but just waiting for the new E-core coil to be delivered in the mail in order to install it. I don't see a way to add a vacuum port on the stock 2bbl, but I was still going to get rid of the leanburn and run as much mechanical advance that I can with the MP distributor, for now, until I find another carb or change to a 4bbl.