Cam arriving tomorrow...whats Ford PN T91P-6565-AH do

Cams arriving tomorrow...whats Ford PN T91P-6565-AH do

..Hey everyone who has recently done the a cam swap with springs..whats this

I have the special spring compressor needed for our 4.6 OHC engines and my new cams arrive tomorrow they are going in this weekend....... But I was reading an article in 5.0 mag(Dec 2003 page 124) and checking the Haynes manual and they both say to be sure to use the spring compressor and the "spacer"(Ford PN T91P-6565-AH) . Something to the effect that over compressing the spring could damage the rubber valve seat/seal if this spacer is not used. I certainly understand not to overcompress the valve springs, I know the seal is rubber/plastic and fragile.

Here is a picture of it. :

Do I have to use this spacer to change my springs. Or can I just be careful and not over compress the springs while reinstalling the valve keepers. Looks like I could slip a washer into the lowest coil right againist the head and accomplish the same thing



thanks