hi guys new to this forum and new to the mopar world. just bought a 1973 dart swinger w/ slant 6 in it . the car wasn't running when purchased(from a guy claiming he was a mechanic) said is wife was driving it when it just quit on her. said he didnt have time to look at it ,but when he tried to start it turned over real slow . now what i did was pull the plugs ,spray wd-40 in but a brand new battery in it and it turned over real slow. after a while of it not turning fast enough i pulled the starter and replaced it . the car fired up after a couple of squirts of gas in the carb so if put 5 gallons of gas in the tank and kept spraying carb cleaner in the carb tilll the line filled from the tank. so now the car runs and drives ive been taking it on a series of small runs to make sure nothing is really wrong with this car. the car fires up at the hit of the switch and runs good however ive noticed on longer drives theres a knock that sounds like the lifters rattling, only when theres a real pull on the motor like right before it shifts from first to second. it doesnt do this if i rev it in park. any thoughts? thanks

Sounds like spark knock or "ping." The first thing to check is the timing. If it's too much advanced it will do that. Other things that will cause it are overheating and too lean air/fuel mixture usually caused by a vacuum leak.

_________________
David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

i would check the bearing, it happen to me one night engine went tight and stalled, after play around with it ( boosting, priming, changing plugs) got it running, once running noticed rattle noise in engine,after a few days a rod let go. when i disassembled engine #1 rod bearing spun and fused two half together sealing oil passage on crank so oil pressure normal until rod broke, i think when piston stuck in the bore.

sounds to me like you have to adjust the rockers