gunk under intake manifold

Looks better than the first v8 swap I did as a kid, I scraped, shop vac, the heavy stuff out.
Stuck the motor in the car, every time before changing the oil I dumped 1 qt of kerosene in the motor and ran it for about 5 miles than changed the oil.
The oil eventually stayed clean.
It was a junkyard motor, so I was only out $50 if it blew up, but it ran for years, until I totaled the car.
Stuck the motor in another car and ran it some more, it did eventually spin a rod bearing, but I got about 4 rough, adding teenage years out of a wore out motor.
I think I blew more centers out of clutches and spider gears in rear ends, than any kid should be allowed.