Funny how the 500 holley ran to rich when I am running a 600 eddy 4 barrel on my 305E. lol
The 351 with the large base 2 barrel would be the one to get. I got a 351 Magnum intake for mine that I opened up for a 4 barrel conversion. Didn't even need an HEI.

Plugs burned clean, but I don't lead foot it and if I do I wait until the right rpm so the secondaries kick in.

I am running a pertronix which helped a tad...mainly for easier startups. Don't even waist money on a 350 2 barrel. They are a rip off for their size.