I don't think that there is any better iron head out there, than the Small Bowtie Vortec, particularly for a 2-bbl.

They will support up to 540hp, and we did 508hp on a gauge legal 4412, with a 355

Edelbrock makes a special tall intake, just for these heads, so you don't have to use a spacer

Can mill them to 46 cc's, and get a lot of compression, even with a flat top