360, I guess you have a pickup? What are you expecting to do?
As noted above, first you have to identify what motor you want to end up with and what you are expecting it to do.

There is a big intake port difference between 2bl and 4bl standard heads for a 390, very easy to tell. old 428 heads are still around and were good on the street.

Old 3310, 780 cfm Holleys with vac secondaries covered a lot of sins and worked well, even in the pickups.

With a truck, you might want torque. Not hard to build a 410 Mercury motor.

As the well respected Tech Inspector said, set your goals and grab your pocketbook.