No such thing as a dumb question. I designed these gears to compensate for the lack of valve train/cam timing adjustment in these engines. When one mills the head and/or decks the block, the pistons are closer to the valves at TDC. The cam timing is retarded as compared to the factory timing in this case. The adjustable gear allows one to get the timing to where it needs to be. The other thing to consider, is that the factory designed these engines to run on 1960's gasoline, utilizing factory components. Many guys are rebuilding these engines for more power, using today's gas, aftermarket parts and simply want one additional option when fine tuning these engines. My Firebird Sprint liked 3 degrees retarded cam timing when on the engine dyno. Your results will vary though, as no engine is rebuilt the same. If you have any more questions, please let em know. Good luck with your build.