350 crate w/12,000 mi. After turning off motor it thump thumps a half dozen times so with a grip on the upper hose it pulses for a minute the fades. I have run it up a 40 % grade with that funnel kit on and revving it over and over to no aval. So is it down to replacing the water pump & I checked earlier and there does seem to slow flow out threw the core. Appreciate your opinion. thanks.