How to fix my knocking engine? on 1991 Dodge D150

The truck starts up and runs fine, but when i get over 20 mph the engine knocks hard and it keeps knocking when I speed up and when it gets past it, It starts to run fine again. Not sure what to do.

by in Belvidere, IL on March 20, 2012
1 answer
ANSWER by on March 20, 2012
THE TRK IS OLDER GET A PRICE ON A GOOD USED ONE INSTALLED THAT WAY YOU DON'T EXCEED THE VALUE OF THE TRK