Keep in mind that the 308s are open chamber. They're also HARD to find without cracks between the valve seats on the chambers on the ends. I went through several, each time the machine shop calling to tell me that they were cracked, before I gave up and went to Edelbrock for heads.
I've heard of people reworking 302 heads for bigger valves.
Because my new stroker motor has a quench-top piston I went with the Eddies that have an open chamber. Summit only lists them for the 340 for some odd reason, but they'll bolt on to any small block. Otherwise, it's the closed-chamber head. Only 2cc difference according to the manufacturer. With my setup with .060" head gaskets and the KB-Silvolite 356 pistons I'll be around 9.5:1, quite a bit more than the stock 8.4:1 that the old 360 had...