what is the easiest way to dissable spark to a 496 ? want to crank with no fire before first start up after winter nap

Why???? Pre-lube?? If that's all, then just fire it.
Prob more risk of damaging something like a PCM or engine electronics by trying to bypass spark.

Pull your kill switch.

Run a lead from the battery to the starter motor

Unplug the crankshaft sensor, but why?

Dude, just pull the kill switch tether. It will turn over, no spark.

But from what you are describing you dont need to, just start it.

Just pull out the oil sender and you can even use a hand pump to put in a couple of quarts of motor oil to oil prime your engine. I do every engine that way to oil prime the engines when needed but by using a air / oil priming set up like what Melling has.

Actually I am a fan of oil priming marine engines that sit for Loooong periods of time.

Actually its not good practices to use the kill switch to crank over the engine multiple times using the 555 s ecms / pcms nor run any jumpers to persay to turn over the engine the engine however nor pulling connectors and letting them hang

Also for the record a fair amount of OEM stock marine engines made in the past 17 years ---- pulling the kill switch will disable even cranking over the engine. Like I said some will not even engage the starter

The best way to disable the spark and fuel is to pull their fuses and or relays. Problem solved. The MARINE OEM s have service bulletins all about this.

Even for distributor engines - I use in the link below - pull out the oil sender out and prime away. This is the current way to oil prime engines -- If one has a distributor you will never go back to pulling that out and using a drill when you have this set up. I have been doing this for over 20 years now on marine engines and would never go back to pulling distributors if applicable.

https://www.summitracing.com/parts/m...hoChQ0QAvD_BwE

doesnt crank

i know its not neccesary but if there is a easy way it doesnt hurt anything either. with all my carb boats i just cranked until i had oil pressure then pumped the throttle to fire.