My 93 T/A has about 74,200 miles on it and still has the original spark plugs as far as i know. So what would be the best replacements? Are NGKs good? And what are good wires for the money?

And is it really necessary to change them out underneath the car...

 

I just finished changing out my plugs on my 94 Z28... If you have an essentially stock car, you probably want to go with stock AC Platinum plugs just because they reallly do last a long time... My original stock plugs were in my car for 125k miles when I decided to replace them... When I pulled the plugs 5 of the 8 plugs had lost the ground electrode platinum "puck" but the car had been running fine... I replaced them with Autolite double platinum plugs in the stock heat range. If the auto parts store had the AC's at the time I probably would have spent a few more bucks for them.
Changing the plugs is a pretty involved process and the wires are just about as bad... I was able to get to 6 of the 8 plugs from the top with the alternator removed... The plugs closest to the firewall I had to get from underneath the car. With the wires, there are many good brands, but if you plan on keeping them in the stock looms, you probably don't want to go any bigger than 7.5mm... It's hard enough to route them with the stock 7mm wires...
Good luck,
Steve

 

A lot of people recommend the NGK's, but I won't use them anymore. Reason being I have seen them come "unscrewed" more than one time. The connector where the spark plug boot attaches "unscrews" from the ceramic part of the plug. I've used Bosch platinums with decent results, and just yesterday swapped those for autolite platinum 106's. Personally, if I had to do it over again I probably would have gone with the 106's to begin with a number of years ago.

For wires I'm running the Taylor Spiro Pros. They've held up well so far.

 

I've been using NGK TR55's and had good luck with those. IMO platinum plugs arent worth the money, yet recommended for the LT1. Pay <$20 for NGK's or $60+ for AC Delco platinums?