Two thoughts on why there can be these hot/cold lash variations on all-iron engines:
- use of aftermarket s/s valves. s/s expands at about 1.5 times the rate of 'normal' steel.
- the steel used in the p'rods.....& just the prods themselves. You have 8-10" of steel tube. The alloying element used with the prod steel might have a high-er expansion rate. Not hard to see a 0.002" difference over 10" of length. Other possibility is how 'heat soaked' the prods were when lash was measured. Once again, slight difference here in temp of the prods is going to make a difference over 10".
