Ok My question and or concern is, I ordered up a set of new hydraulic lifters for my 340. Old ones were moved out of there running order while sitting around the garage. So I order up a new set. Now comparing a new lifter to the ones that were in there the new one is a hair taller. Now the ones I ordered are Comp Cams 822-16 with a seat height of 1.88, Now after seeing the difference in the heights I think the ones that were in there first were the Comp lifter 867-16 with a seat height of 1.84
Now, can I just install the new set of lifters with the higher seat height OR do I need to return them and order up the shorter height lifters?

The .040 is a big difference since it already had the
preload in it... I dont know if thats .040 is more or
less preload(I dont know if they measure from the top
or the bottom)..so are you adding or subtracting the .040

Do you have a way to check the seat height of the old ones? if not find a machine shop that has what they a height mic, the ones we use at work are nothing more than a 2" travel indicator mounted on a granite base with a pedestal to mount the indicator to, or try a set of 3" od mics with a 5/16 ball bearing in the cup, then you will know for sure.

If you have a vernier caliper you will be within a
few thou and that will be close enough...if your preload
is a couple of thousands off it wont matter... but .040
is getting quite a bit out of the range they want... I
dont think the tip of the caliper will go into the hole
at the bottom of the cup... just check it... that way you
wont need the 5/16" ball
I guess I can go out to the shop and see if the tip will
go in.... stand by.... I measured from the top to the bottom
of the seat(where the ball would sit)and the tip of MY calipers
didnt go into the hole..from the top on mine solid roller it
was .618...so their numbers must be from the bottom of the flat
to the inside at the seat...if you want just measure each one
the same way so you know the difference

I called Comp cams twice, both times 2 different techs recommended the 822-16 lifters with the cam I have in there.
I asked about the other lifters listed on Jegs web site advertised at the 1.84 seat height and they told me that Comp does not offer one for a SB Mopar???
Anyway I'm going to stick with the 822-16 lifters.
Thanks for the insight guys even though some of it was beyond my comprehension.