My 89 chevy is making a knocking sound i just

with it running pull 1 spark plug wire at a time with good insulated pliers and dry gloves (60,000 volts) no amps ...if you pull a wire off and the knock gets worse then the connecting rod bearing is bad on the opposite side / same crank throw , do ea wire till u find 1 that makes the knock get worse if not it may be the main bearings, try a thicker oil or oil additive .worst is you need to turn the crank and get new bearings . you rebuilt the top and not the bottom ?

Did you check the knock sensor located on the passenger side of the block, behind the starter, The sensor can be bad sending a signal to the Computer causing the computer to readjust the spark advanced timing causing Knocking and pinging....... or it could be as simple as bad gas. If you changed the timing chain, the gears should both be set with the the timing marks at 12 oclock for the 89 chevy K1500 5.7 350 V8 TBI OHV 16V if you set the timing at 12 oclock on the cam and 6 oclock for the valve and Distr. the number 6 is firing as number 1 you can recheck by bringing the No. 1 piston back up to TDC and check to see if your Distr. is pointing to the No. 1 Plug Hope this helps

ck if you have the right amount of oil in the engine