LA360 Octane

Just figure it out the old-fashioned way, with a compression test
Start with a fully charged battery
remove all eight plugs
the throttles should be WOT
crank until you get two successive readings of same or similar numbers
Record ALL the peak-numbers, keeping track of which hole made what pressure.
Your battery has to keep up, or it will take more and more cranking with each test.
Do not put anything into the cylinders on the first go-round.
Ideally the engine should be warm, or recently run, but summer ambient is not a deal-breaker.
Numbers around 155 to 160 are ideal. Over 160 may be an issue. Below 140 is gonna be lazy on take-off with a stock stall-speed, and lazy thru the gears with sub 3.00 gears. Tall tires will make it worse.