Old post, havent been paying attention lately.
I was running twin 750 4160 Holleys. Worked extremely well on Moo's old engine! Fuel efficent (As far as T/R's go) when you kept the foot out of it, and balls out when in it. Plugs were always a dark tan color and very even. No idea what jets/pumps were in them, bought them new from a dyno shop here in Tucson that tried, and tuned the hell out of them, for a T/R BBC and ended up switching to 600's. They were just too much I guess, but with my combo, worked great as soon as I bolted them on! Moo's 460 motor was pretty far from stock, Nordies old 429 was just as it came out of a Station Wagon as I understand it.
I beleive Nordie was running a single 850 DP Holley. Could be wrong, but his talent in carb setup made it work somehow, and work WELL! (I'm not a fan of single carb T/R setups).
You know you got it right when you can make a smoothie scraping the ice off the manifold and your plugs look good and even!

Biggest thing on, well, really any engine for that matter, is read your plugs! Much more important on pseudo extreme deals like a T/R or extreme deals like a Blower.

Ray