If you are referring to the tool that would compress the valve spring so you could remove the cam follower, that tool is a Ford specialty tool that has not been made for years and is very hard to find. I believe Esslinger makes a similar tool new though if you want that.
I'm not familiar with the seal puller tool you refer to. Is this a standard spring compressor or possibly one that fits over top of the retainer and reaches down to grab the spring coils and compress the spring?
Looking at the manual, it appears a special tool is needed to relieve lifter preload or valve spring preload so you can get the follower out from under the cam lobe. Until you remove the follower, you can not remove the spring retainer to replace the valve stem seals.
Maybe I'm overcomplicating things. I simply want to replace my valve stem seals. I do not want to service my valvetrain as it works fine and low miles.
Tool compresses valve springs on most overhead valve engines including GM, Ford, Chrysler, Nissan, and Toyota. Jaws adjust to fit over spring retaining washer. An adjustable handle allows easy clearance in tight areas. GM adapter included. Use 3269 Fulcrum Rail if overhead cam is not available. Use with 901 or 2992 Air Hold Fittings to keep valves in place.
I'm just talking about your standard seal puller that you'd find at Sears or any auto parts store. You hook it under the cam, and use the other end to push down on the spring retainer until you can pop the follower out. The handle on the seal puller gives you plenty of leverage.