How hard is it to get to all of the spark plugs,
hell I cant even see half of them is there some trick to a regular tune up, also I seem to here what sounds to me like a "squish" sound coming from under, around the rear of the car, right before it changes gears what in the world could that be......Tranny?

 

what year is your car? 93-97 or 98+

 

Sorry 95z28 with auto trans

 

i'll give you the trick to changing spark plugs.

driver side:
front three can be accessed from the top, back one go in from underneath. they are tricky but not too bad.

passenger side (comonly considered the worst):
remove the alternator, remove the pass. side motor mount bolt (15mm socket on front, 18mm end wrench on back braced against the frame rail/crossmember). jack the engine up 2 inches or so. this allows you to access ALL the passenger side plugs from the top.

if you want to install new wires too, get some 8mm ones, i used taylor spiro pro's from thunder racing for $50. 8mm wires fit into the stock wire looms. to get to the loom channels on the front/passenger side, remove the tensioner pulley since you'll have the belt off anyway to take out the alt.

first time doing it, by myself, new plugs and wires routed through all stock looms and i did it in 4 hours.

 

http://csce.uark.edu/~jgbertr/rb/4th_gen_tech1.html

this link has alot of information that will be useful for you if you are a do it yourself person.

Spark plugs...hehe, with those stock manifolds, its not the easiest of jobs, can get some from under the hood, can get some from under the car etc etc etc...but it can be done at home. I would set atleast half a day aside since it is you first time changing them out. You will learn as you go believe me.

 

First time changing plugs on an LT1 is definitely a learning experience. My first time took 12 hours but I changed the wires too. The second time only took me 2 hours. You will pick up a few things to help you out on the first install. Just take your time and take lots of breaks if you get frustrated b/c trust me it is frustrating.

 

The best tip I have ever gotten for doing the plug under/around the alternator, is USE A 1/4 inch drive ratchet with the appropriate fitting to adapt 3/8 inch drive sockets. Yes you still have to take the alt off, and you'll have to use a standard 3/8 drive to break it free, but once it's loose you can remove it easily with 1/4 drive ratchet.

The rest just go from above or below as circumstances dictate. They're easy! You should be able to do it in right around one hour.

 

You can save yourself some time and heartache by waiting to change the plugs until you put on a nice set of headers. I can change the plugs in my car in maybe 20min, and that's while goofing off. For the one behind the alternater....go to Sears and get a 3/8" swivel joint, it'll make that bend a lot easier.

I'm not sure about a "squish". It could be the tranny mount, u-joint, rear gears, problem with the yoke, exhaust hitting something, and bad shock/spring, etc.

 

20 minutes with MAC headers? That's a HUGE plus. Try 4 hours on the Edelbrock TES Headers...