Looking for advice on using hydraulic or mechanical lifters in a 235CI engine in my 55 1st series 3/4 ton. Currently the engine has hydraulic lifters but I have considered swapping them out since they need to be replaced anyway (some are cracked on the top). What are the advantages/disadvantages of each? Also, do I need to change the cam if I change to mechanical lifters? The truck drivetrain is somewhat modified, but not to any extreme. I am putting in a Saginaw 4 speed and swapped the rear gears to 4.10 but not much more. As always, any and all advice is greatly appreciated.
