Isuzu trooper 1994 3.2L what type of spark plugs should be used?

I have a 98 3.5L with 175,000 miles.

I just put my 2nd replacements - 3rd set overall.

Got the best buy at local autoparts - not the chains. Bought Denso which were less than Bosch etc and I believe Denso is OEM.

PS - they are fairly easy to replace, but get extension bars and a universal joint.

(Keep those receipts)