Has anyone tried the Pulstar spark plugs in the 305 Olds engine? They look fairly promising, but I know mucho chiquito about automotive engineering on both the drawing board & practical ends. Also, at $200.00 for 8 of those puppies getting a few opinions could save a few $$ :-)
Olds made a 307, not a 305, Chevy made a 305 and 307, the 305 is related to the 350 and the 307 is related to the 283, 302 and 327.
But aside that, plugs like that aren't going to get you much over a good tuned stock ignition, best to save your $ for the gas tank. $200 goes a lot farther than if you are lucky, 1mpg improvement.
Put a set of NGK non platinums in there, maybe a slightly narrower gap than stock, down to 0.045" is often beneficial for ideal ignition. Avoiding platinums is important to reduce pinging. Platinums were required indirectly by the EPA to have longer plug life (as most people are lazy and don't change them like they should want and EPA wants 100K emissions min life).
307's are going to be high hp engines without lots of mods, but can be made to run better given some good attention to detail.
The hot rod community has really taken a shine to the plain NGKs like the TR5's/TR55's. Keeping the gap smaller like in the 0.045" range has proven to reduce misfires, smoother idle and better (proven on dynos and at the track) WOT power. My 454 L29 got a much smoother idle and I get low 14's for highway mpg with it too. That is tough to do on a 454.... trust me! I still can't figure out with modern EFI, roller cams, decent heads/compression and OD I can't get 16's.....