Oil Pressure went high and 3 connecting rods burned out

Was the engine oil level correct?
When taking delivery of vehicle, was there any abnormal engine noise? If the noise was there, most probably the previous owner would have known something about it.

With damage to the crankshaft and connecting rods. A replacement engine would be a better option.

Replacing the parts could be as costly as replacing the engine as there are major damage to it.

I JUST GUESSED YOUR ENGINE SIZE

THIS IS A RE-MANUFACTURED ENGINE FROM A PARTS STORE.....TO ME IT'S JUST LIKE HAVING A BRAND NEW ONE

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_spartan-remanufactured-amc-jeep-engine-spartan-atk-engines_20706538-p?navigationPath=L1*14923%7CL2*15031%7CL3*16033

JUST A WILD GUESS...I'D SAY YOU MIGHT GET YOURS "REBUILT" LOCALLY AT AN AUTOMOTIVE MACHINE SHOP, IF THE BLOCK/CRANK/AND HEAD ARE USABLE, FOR $1000-$1200

DEPENDING ON THE LOCAL SALVAGE YARD....A USED ENGINE MIGHT GO FROM $300-$1000.....THE LITTLE "SELF SERVE YARDS" SEEM TO BE LESSER EXPENSIVE....CALLING THEM SAVES TIME

POSSIBLY REMOVING AND TEARING INTO YOUR MESSED UP MOTOR, POSSIBLE MACHINING AND PARTS....WOULD BE JUST LIKE A "LOCAL REBUILD"....EXCEPT YOU ARE STILL STUCK WITH A MOTOR APPROACHING 200,000 MILES

"MY GUESSING" DOES NOT REFLECT "LABOR", IF YOU ARE NOT DOING THIS YOURSELF

OUT OF CURIOSITY---THIS PUPPY DID NOT THROW A ROD----WHEN YOU DID CHECK THE OIL LEVEL, AFTER THE FACT, HOW MUCH WAS IN IT?

AROUND HERE "AS IS" IS HOW MOST USED CARS ARE SOLD----SO REALLY, IT DOES NOT MATTER "WHAT WAS SAID".....THE ONLY THING THAT CARRIES WEIGHT IS SOMETHING IN WRITING

I CHECK WHAT I CAN CHECK ON THE SPOT...I EVEN PULL THE FILL PLUGS ON DIFFERENTIALS, TRANNYS ETC......I WANT THE BEST INFO I CAN HAVE BEFORE I BUY...SEE MY ANSWERS IN THIS LINK

https://www.2carpros.com/questions/2001-ford-f-150-grinding-noise-upon-light-braking

WHEN I GET THE VEHICLE---I CHANGE EVERY FLUID IN IT...ALL EXPENDABLES TOO (DIST CAP--FUEL FILTER--ETC)....I INSPECT THINGS LIKE THE BELTS AND MAKE A JUDGEMENT CALL.......I TRUST NO ONE!....NOW I CAN START AT "ZERO" WITH MY MAINTENANCE PROGRAM

IF YOU REALLY ARE FALLING IN LOVE WITH THE VEHICLE

FOR THOSE WHO DON'T KNOW HOW TO CHECK A VEHICLE WELL---ASK IF YOU CAN TAKE IT TO A SHOP FOR A FULL SCALE CHECK UP (NOT A "LOOKS GOOD--DRIVES GOOD" SHOP)

THIS WILL COST SOMETHING...FOR SOMEONE TO GO OVER IT WITH A FINE TOOTH COMB

IF THINGS DON'T WORK OUT WELL---TAKE IT BACK TO IT'S OWNER---SAY NOTHING ABOUT WHAT WAS FOUND WRONG! ! ! ! !

....UNLESS THE OWNER WANTS TO "BUY" THE "HEALTH RECORDS" YOU JUST PAID FOR!

I JUST CAN'T PICTURE ME, TELLING THEM, WHAT NEEDS TO BE FIXED...FOR FREE...WHEN I JUST PAID FOR IT!

IF THE INSPECTION WENT WELL....YOU HAVE PEACE OF MIND, KNOWING AN AUTOMOTIVE EXPERT, CHECKED OUT THE VEHICLE......NOT FRED, THE FLORIST, YOUR NEXT DOOR NEIGHBOR!

THE MEDIC

If the original is a V8 and you are replacing with a V6, it requires more than an engine replacement. The wireharness and engine computer would have to be replaced as well. What would the cost be like?

That would seem a reasonable cost if it includes everything.