Not hip too the lingo yet, what are LSD and AT? Is there a preferred place to the get the main pulley bolt? I downloaded the Service Manual, I figure I can get it replaced with that but do you have any specific things to do or watch out for when I go to change it out?
LSD: Limited Slip Differential. Provides better traction by making both tires spin.
AT: Automatic Transmission. Similarly MT will mean Manual Transmission.
Dealer item for the main pulley bolt. There are some online dealers. I don't remember them off the top of my head but I'm sure others will chime in. Probably not much difference in price for it assuming you'll also pay the shipping fees so it may be better for your local economy to buy from a local dealer than an online one.
Timing Belt: If date of last replacement is unknown it should def be inspected and if any signs of wear are found then replaced. Biggest thing to help when I did my 90 was my brother-in-law who had done it before. You'll def need an extra pair of hands to help remove the crank pulley bolt unless you do the starter trick. My brother in law had seen things break doing it that way so we did it by removing the starter & holding the flywheel in place with a big screw driver as we loosened the bolt.
There are timing marks on the pulley and block that you can use to re-align everything.
It will also be a good time to flush the cooling system, replace the water pump & the o-ring behind it, tensioner pulley, idler pulleys, and other belts since you'll have access to everything.
If the engine has leaking valve stem seals (dark smoke during cold start up or when revving after an extended idle) then it may be a good time to replace them as well because you'll just have to redo the timing belt removal & replacement process again when you eventually do them. That said, there's a couple of ways to do it w/out removing the heads (LP air or rope tricks).
HTH.
