Ouch James, it finally gave up huh...lived a good life.
Only way to put a Holley on a 351 is with a custom set of manifold spacers, and really it isn't ideal.
I would go with a Vic Jr or Super Vic Spyder, all your EFI stuff will fit (not sure if you already have rails or not, thought you did). If you need some pricing let me know, I can get DART blocks at a decent price and they do not require half the machining that the Rblocks require.
How much are the 351 dart blocks? I was planning on doing a 357 N/A combo, any advantages of using a dart block over a stock 351 block? Im not planning on nitrous or anything.