Headers and dual carbs are a waste of time and money. You'll end up with worse performance with dual carbs than with the factory setup.
I'm sure HRL will be along to tell you about a modification to make your rear main seal leak proof forever.
I like breaker point ignition and use them on all my cars with no problems on actual daily drivers. If you must use HEI, read the threads concerning that on this forum.
Here is a company that will convert your original dizzy to HEI using GM components.
Converts your original points style distributor to GM HEI system
DAVE's small-body HEIs
24 Buffalo Lane
Yerington, Nevada, 89447
775- 722-3294
[email protected]http://www.davessmallbodyheis.com/