Well definitely talk to @[deleted]. Yours will have two chains like mine which will be the main timing chain and a balance shaft chain (having re-read your post and not your profile lol). As i said, VX recommends changing them at or before 100k so yours are due now unless you know that they've been done. I thought mine was fine as to my ears there wasn't anything of a rattle but when Carl heard mine he immediately said that the balance chain sounded loose. He was spot on, my main chain wasn't bad but the balance chain was worn to the point of contact with the casing. The thing is, if your doing one you might as well do the other. As per advice to me, definitely use a GM main chain but you can use a FAI balance chain as it's not as critical. You'll need to make sure you've got everything like gasket, crank oil seal, oil and filter and some sealant just in case you have to drop the sump. The main guide can self destruct and fall into the sump area which will have to be cleaned out if it has (or it blocks the oil feed and then your engine suffers from a lack of oil). You may be lucky and have no issues but I would definitely recommend doing the chains regardless if you have no proof of them being changed. After that, well, as I was told, regular oil and filter changes every 3K-5K. Mines had one since mine were done at the end of January (the filter was in perfect condition and only just starting to collapse) at a little over 6K only because I got my nephew to do it along with some other work . Will have another at 100K making two in 10K since the change of chains. The other issue you can get is the filter collapsing due to poor maintenance (hence the regular oil/filter changes) which can get so bad as to end up going through the engine.