Disassemble the block and have it cleaned. Then have your crank turned and all your rods checked. Install new bearings, rings, oil pump, timing chain, gaskets etc. then reassemble the engine. That will get you back on the road temporarily.
If you want reliable transportation..... Spend the money to do a complete rebuild on the engine, and heads. Also have the trans checked and at a minimum have the fluid flushed and the filter replaced. Then GET RID OF THAT 6 CYL RADIATOR! Install a V8 radiator and a trans cooler. If you're running a high stall converter you need a trans cooler since the high stall on the converter creates more heat and excessive heat will destroy your trans quicker than anything else.
Bottom line..... do it right or you'll be doing it again soon.