Ticking, Knocking noise! checked pushrods?
Trending Topics
The Best V8 Stories One Small Block at Time
Other things to check:
AIR system
Make sure plugs are tight
Pushrods / Rocker arms
Valve Springs
Lifters
But to check the lifter, you will have to pull the heads.

Lifters are in the rectangular holes at the top.
-May cause it to run rich with this situation
-Running rich can fowl out plugs and ruin O2's if it is bad enough

http://www.installuniversity.com/ins...g_and_wire.htm
or
Most people / write ups will say use and extension/swivel, but the 2x I have done it, I can just reach back there and get it.
I do not have small arms by any means, but they may be longer than other peoples. I start at the front of the engine, and reach right along it, under the coil packs (slightly left/lower than the vavle covers), and I can reach it from infront of the car. (Using my left arm) Using this method / similar method, I can change all the plugs with a standard 3/8 ratchet and spark plug socket.


