First of all DAMN for having a 89 SHO with 55k on it(if that is on the motor AND body that is).
Second you'll need to get a shim kit for doing the shims. Shobill has a really good one and you can locate him on the classifieds in a big thread about his shim kits.
Last you'll just need a bunch of metric sockets of all sizes as well as a few assorted standards but it is almost totally metric, you'll need a harmonic balancer puller, and various random tools such as pliers, mallets maybe a torch(i was lucky and didn't need a torch) a good torque wrench for the crank bolt (120-130 ft lbs) and another good torque wrench in inch lbs for the valve cover bolts and intake bolts(you can use ft lbs but I found an inch lb needle torque wrench to be more accurate).
You NEED to use torque values for the vc and intake bolts especially the vc bolts. You would be amazed at how easy they snap. I snapped two of them just tightening by hand with a small allen wrench and had an epic easy out adventure which somehow ended in success. 144 inch lbs for the vc bolts and 200 inch lbs for the intake bolts. Everything else can be german torqued.
But yes that link cerberus posted is for the most part correct for the MTX. For the ATX it can be a bit confusing but that isn't a problem for you.
Do the shims now while you have it all apart
Do the front main
Do the cam seals
Change the crank position sensor
Change the timing belt
Change the accessory belts
Maybe do the waterpump too while you're in there since you have to tear it all apart again to get to the pump if it decides to crap out on you. They usually go before 100k.
Get all the seals and belts and other parts from rockauto, don't waste your time with the idiots from autozone/advance/pep boys they'll order the wrong stuff. As for wires and plugs well... nobody seems to have the correct agsp 32pp plugs anymore. The autolite and motorcraft replacements are too tall and don't seal properly, even the densos I got that were suppossed to fit didn't quite fit properly so I put a bead of rtv around my new wire boots to seal everything up. Taylor wires work great as do the motorcrafts and delcos.
Trying to think of other shenanigans I ran into since this was my first time... Um, make SURE you hook all the coolant lines back up, there is one that attaches to the upper intake right behind the throttle body that I missed and now my hoodliner smells like coolant. Also make sure you get the plug wires routed properly, there is a sneaky order to them which you'll see on the sho phoenix site. It goes 123465. Other than that I think you'll be good to go. It isn't that complicated, any decent backyard mechanic can do this in a few weekends on the first go. Now that I've done it once I am confident I could do the whole thing in one weekend.
