Scored Main Cap Bearing - Ouch
If you insist on the flush, I have flushed with diesel but not running. I am NOT recommending you use diesel or kerosene running. I really think you should just use it as a 'wash': pour it through, and let it run right out, to try to get out any stuff lying in the heads, and pan.
If you want to go hard-core with this: I actually put a full load of diesel in an engine that had coolant in the oil, and them primed the engine with diesel, while slowly turning the engine over and over by hand, to get it to go everywhere. Drained and repeated with diesel. I also pulled the lifter one at a time while doing this, starting at the one closest to the pump, and also tapped the lifters to get the old oil and junk/coolant out of each one. Then drained the 2nd diesel load, put in cheapo Walmart thin oil, and then re-primed for a while, while slow turning. Drained and primed and turned again, with a new batch of cheapo oil. Then drained that 2nd batch of thin cheapo oil, and put in a 10W30 Walmart oil, reprimed, then idled 'til it was warmed up, then drained and put in another load of cheapo oil, ran and changed that oil after 10 miles, and finally put in the oil I wanted. IMHO, oil is suuuuuper cheap compared to the time and expense of this engine work. (BTW, this process worked really good to get the coolant out, which had gone everywhere.... but then I found a massive head crack LOL.)
But I am really questioning if this is necessary in your case.
Complicated, I have a solid lifter mtr and am leaning more for the drain run and refill. By the way the Walmart oil is made by Warren Oil Co. in Louisiana. I have been using it in all my vehicles for over 10 years. Its in my Dart right now 10W40 conventional, 120K with the syn in my Genesis and never a problem. Here's a spec sheet for their synthetic oil.
Warren® Full Synthetic GF-4 Motor Oil
Warren Oil Company, Inc
Dunn, NC 28334: Benton, AL 36758: San Antonio, TX 78210:
Marion, IL 62959: Johnstown, PA 15909: West Memphis, AR 72301
WARREN FULL SYNTHETIC GF-4 MOTOR OILS are
superior-quality, high detergent automotive engine oils specially formulated
to meet the stringent lubrication requirements of today's engines. Synthetic
base oils combine with a carefully selected additive package to provide
maximum protection against wear, rust, corrosion, oxidative thickening, acid
formation, sludge and varnish deposits.
WARREN FULL SYNTHETIC GF-4 PASSENGER CAR MOTOR
OILS (PCMO’S) Meets or exceeds the requirements of MIL-1-46152E,
Ford WSS-M2C153-H (SAE 5W-20) and WSS-M2C930-A (SAE 5W-20)
and WSS-M2C929-A (SAE 5W-30). Meets DC MS10797 (SAE5W-20),
DC MS10796 (SAE 5W-30) and DC MS10798 (SAE 10W-30)
specifications. Meets Honda Service Fill Specifications. Meets GM 6094M
specification (SAE 5W-20, SAE 5W-30 and SAE 10W-30). Meets Toyota
specifications. Meets API Service Category SM, SL, SJ, SH complies with
ILSAC GF-4 requirements.
Benefits
Our highest level of protection for thermal and oxidation stability
Helps protect emissions system
Minimized rust and corrosion
Outstanding low temperature pour point
ILSAC GF-4 Energy Conserving
