You could also go with AC Delco 41-101 (Iridium) available at Autozone for $6.99 a pop. I know that sounds expensive, but they're supposed to last 100,000 miles. I still have the factory 41-921'* in mine and I have over 90,000 miles on them.
If you come up with a magical solution to changing the back three, PLEASE LET ME KNOW.
It'* a big help if you remove the engine hoist bracket from the back drivers side of the engine. I believe it'* the MAP sensor thats connected to this bracket but it can be zip tied else where. I'm pretty sure the bracket comes off with a 13mm socket and it'* done pretty much completely by feel because you can't see where it'* connected at, be patient. It can be a pain in the a** but the arm space it opens up is definitely worth it. The first time i changed my plugs it was really hard but i did a search on here and saw a post by Rogue where he suggested removing that bracket and it makes all the difference. I have found its alot easier to reach the back plugs from the passenger side too if that helps at all.
I'm pretty sure the bracket comes off with a 13mm socket and it'* done pretty much completely by feel because you can't see where it'* connected at, be patient. It can be a pain in the a** but the arm space it opens up is definitely worth it.
I can barely get to the nut on the driver'* side of the bracket, but not the passenger side.
I'm thinking of removing the alternator and drive belt tensioner. That way, I might have a way to get my left arm/hand in around the power steering pump onto the rear plugs.
The rear plug on the rear driver'* side I can get to with my right arm/hand. Reaching around the trans dip stick tube is challenging on that one; plus there'* some EGR tubes in the way too.
I do all the plugs from the passenger side. Get a ratchet that has the gnarled circular head (with a ring you can turn to rotate the socket) then slip the socket on the plug with your left hand go back down with the ratchet (with a 3 inch extension on it) and rotate the head of the ratchet util it lines up with the socket and press in to engage.
I am getting ready to replace the plugs and wires on my 2000 SSEi and I know that the rear plugs are difficult to get to but the #2 and #4 are easier to remove from below the vehicle and #6 should be removed by leaning on the driver fender and using a universal joint on a 1/2 inch rachet with a short extension and that works perfectly OK.
I found it easier (not easy - as it'* not ) to get the plugs and wires from above. Wear some protection on your arms, as they will get scraped up pretty well from the hose clamps for the heater hoses. The wires are the hardest problem. If you can get those off - you're home free. The plugs are a breeze in comparison.
For me, there were just too many things in the way to get to them from below. That'* not to say that some won't find that to be the better route.
Even though I posted a possible way to replace the spark plugs and wires, specifically on the #2 and #4 cylinder, Archon was absolutely correct because I changed all the plugs and wires last night on my 2000 SSEi. I did exactly what he said and it worked perfectly!! He is a great guy. I took a rag and wrapped it around the heater hoses where the clamp is so that it wouldn't hurt my arms and although the whole process took about 2 hours, it worked excellently. Also, I am confirming that the engine hoist bracket on the rear requires a 13MM socket which is exactly what Archon indicated. I used the NGK plugs and the Beldon wires. Thanks for all the great advice and help by our BC administrators!!!