and valve cover gaskets. Any suggestions the best place.
Alo, why are the seals so important for the spark plugs? I never did the job before.

 

There are several places from which to purchase.
Do a google for Jaguar XJ8 parts suppliers.

The plug seals seal the plug tubes from oil ingress from the heads.
Oil in the plug wells is a sure sign it's time to fit new seals.;o)
Be aware there are two different types...the 'linked' type are for earlier engines (AJ26) and the later ones are seperate (AJ27).
Also the cam cover seals are slightly different for the two engines....earlier are 'B' bank (drivers side-LHD) is orange and 'A' bank is grey.
Later engines both have grey seals.
If you are going to replace cam cover seals it pays to also replace the screw seals.
Your car is an AJ26 so go for early seal kit.

 

You can buy the spark plug seals online or at your local jaguar dealership parts dept.
Part is NCA2578BB - you need 2 of them for each side - a total of 4 to do both sides.

I called our local jaguar dealership parts dept - they quoted me $9.67 each - $38.68 for 4 of them plus 6.35% sales tax plus a 30 mile round trip to them. (It is in stock).

Gaudin (gaudinjaguarparts.com) shows list price of $5.20 each (discounted to $3.95 each) plus fixed shipping $14.95 for a total of $30.55.

Car parts disount (carpartsdiscount.com) item# 121198 Eurospare price is $4.15 each - $16.60 for 4 of them plus $7.07 shipping for total of $23.67.

3 other internet sites also sell it at around $27 for 4 with shipping:
motor cars ltd, welch enterprises and coventry west.

You can buy the complete valve gasket kit on ebay Item number: 350230212346 $89.00 plus $10.95 shipping:
Christopher's Foreign Car Parts (THESE ARE THE THICKER GASKETS - LEFT B BANK SIDE IS ORANGE, PART # NCA2516AE - RIGHT A BANK SIDE IS GREY, PART # NCA2515AE -COMES WITH SPARK PLUG SEALS AND GROMMETS)

Your AJ26 engine spark plug seals and the related all inclusive gasket set unforunately are a lot higher priced than the AJ27 engine ones (that are available as Lincoln LS felpro ones).

Jim Lombardi