A little Help with my Heads. (Motor 2)

Hey All, Thanks for taking the time to read my post. And a BIG Thanks in Advance for helping me!

Ok Here we go, I have a 1975 360 Block. I'm the 3rd owner, I've never had the motor apart. Long Story short I replaced my timing chain. It was really Slack and I couldnt set my Ign timing properly. Ok I replaced it. And I still got a "Pop" out of one bank of the exhaust (I have headders) To me it smelled Rich but the POP ocurred in the Headder..(MSD 6al IGN and Dist) Leading me to believe a Burnt Exaust valve. So , I Yanked the heads today....

Here's the Pics....

Left Head http://i456.photobucket.com/albums/qq285/Eric_s68FL/Picture0108113.jpg

Right Head http://i456.photobucket.com/albums/qq285/Eric_s68FL/Picture0108114.jpg

Left Bank http://i456.photobucket.com/albums/qq285/Eric_s68FL/Picture0108116.jpg

Right Bank http://i456.photobucket.com/albums/qq285/Eric_s68FL/Picture0108115.jpg

The Casting # on the Heads is 3418915D / 04090

I have a Holley Vac Sec 750Cfm (outta the box) and an LD340 intake manifold, 15 year old Hooker Headders I think (1 7/8")

I do not know the cam profile, I will attempt to measure that soon (it is radical)

The car runs Track only...

So, Here's the Questions:

1) Are the Pistons in the pics Stock? That will tell me if I will dig deeper..

2) What Should I do to the Heads? Just a Clean n Valve Job? (I plan a future 408 build with this block)

3) Keeping the machine work and expense this go thru to a minimum What would you do?

I gonna Pull the Block anyway cause I have a new Verter like a 3500-4000

Right now, I'd Just like to have the 360 running well..

Gimme your Ideas n thoughts ! Thanks again !