You need a compressor that will work around the cam.
The simple screw type needs direct access to the top of the
valve.
Definately change the valve seals and the oil supply elbows on top of the cam bearing caps. Mine were brittle and broke when I
gently pried them off, leaving pieces of plastic in the holes which
are a pain in the A** to fish out.
I'm just finishing up my 420. Read and re-read all the posts.
Pay attention to not letting the chain jump time.

Regards,

__________________
Thanks,
Mike

'83 300D
'87 Volvo DL Wagon
'88 420SEL (SOLD)
'98 Toyota Camry SE V6
'96 Ford Brono XLT
'94 Mercury Villager
'46 Willy's CJ2A
'40 Packard 110 4DSD

"Just another squirrel, trying to get a nut"