Mild 383 build

I'd go with the 440 Source Stealth and have them ported the SNOT out of. They're a good combination of budget and quality. Regardless, make SURE you get whatever head you use checked out. Jim Laroy has made BIG power with them in the past.
https://store.440source.com/Stealth-Aluminum-Cylinder-Head-COMPLETE-SINGLE-HEAD/productinfo/200%2D1055
This head?