late model slant six head

Heads are all interchangeable, valves are not Hydraulic, lifters are. The lifters,pushrods,and rocker arms on hydraulic adjuster engines are completely
different. The system actually oils the hyd. lifters "backwards" from the rocker
shaft, through the rocker arms, and down the pushrods which are hollow, into
the lifter through the pushrod cup. It works, odd as it is,and was neccessary
because there is no oil passage to the lifter bores.
Dot.org has the run down on the combustion chamber changes, later heads
w/the external spark plugs all have the more desirable chamber, tho' they are
a good 12 to 15 lbs. heavier. Either way, you're good to go on your swap, just
make sure you use your valvetrain if that engine happens to be hydraulics.
Cheers!!:coffee2:
P.S. valves were same 1.62/1.36 pair for the 30 yrs. of production regardless of lifter type,
same for the rocker shaft.