Loose rocker

64ss409

Well Known Member
Supporting Member 9
#1
A little history on this engine. In 1967 or 68 I bought a used 1965 400hp JA engine to replace the 261 in my 1958 2 ton grain truck. (the 409 owner had a Chevy garage replace it with a new crate 427) I took out the 11 to 1 pistons and put std truck pistons in the car block. I replaced the solid cam with a hydraulic 340hp cam. It has run good and been trouble free for 50 years. Last week it got a tick on the left side. It quickly got louder and started to miss. Yesterday I pulled the valve cover, not easy with 2 speed vacuum lines too close to the valve cover at the firewall. Not to mention stiff back and bad knees. No 5 intake rocker was loose. I'll get a new nut and re-adjust, but I thought it odd that after this long one rocker got loose.
 

wristpin

Well Known Member
#5
Tighten as you said then turn crank over by hand. Measure lift from zero to full lift with dial indicator. Determine if loab is flattening. If it is you may have saved your engine. You may want to pull the intake and pull the lifters and see if they are concave. Id pull intake and not screw around and pull every lifter and eyeball every lobe.