Your shop gave you the wrong gaskets...
Some hints for the newbie:
1. If you are clearancing yourself, get a high speed rotary tool of some kind. Makita hand die grinder, dremel, or if you have air a die grinder and a cylindrical carbide burr.
2. Remove the heads from the engine, and if it were me I'd disassemble them. You will need a new set of positive vales seals because they don't do well with being removed in most cases. Keep track of the valves and put the same valve back where it came from.
3. When you're done, clean the heads well, especially with a degreaser and make sure there's nothing down in the guides (use brake cleaner or a cleaning brush if you have them).
4. Use assembly lube or thick oil on the stems when they get reassembled.
5. If the camshaft is a flat tappet of any kind, and required true double springs (that's two round-wire coils with a flat wound steel dampener between them) - remove the inner springs and omit them when the heads are assembled. They need to be out for cam break in, then re-installed afterward.
6. Buy the Felpro Performance 1009 head gaskets. They have a pre-flattened fire ring which is necessary for use with an iron block and aluminum head combo. Standard gaskets will work, but over time they will brinnel the head (meaning they will erode the aluminum off the head through repeated heat cycles). This can lead to sealing problems down the road.
7. Use a thread chaser or tap on the holes for the head bolts and blow them clean with air or brake clean.
8. Use the right lube on the threads (ARPs need the ARP lube and use the ARP torque specs) and torque in three steps. The last step should be a smooth pull up to final torque value.
9. The rockers you run may have some benefit from a spacer package. I think Mancini sells them, maybe Hughes too? Shim the rockers to achieve .010"-.015" clearance between them.
Hope that helps!
