nah im not sick just busy for once i know, shocker. teh s13 doesnt have perfect 50/50 weight distribution, not that it makes a huge difference though, it helps to relocate ur batter to the rear to bias a little more weight to the back. dont mount it to far back thoguh or u'll get an unwanted pendulum affect. also when stitch welding the chassis, make sure to stitch weld and not seam weld. u want to some space between teh welds so the chassis has some flew or else the welds will brake. whenever u get a new car, check for rust and any maintenance related issues. theres no sense in have a massive turbo if ur factory brakes cant stop u soon enough. after any rust is repaired and basic maintenance is performed, focus on braking a suspension first. if u dont wanna shell out too much money go w/ the z32 brake upgrade
http://importnut.net/300zxbrakeswap.htmor the q45 brake upgradehttp://forums.nicoclub.com/zerothread?id=291886as far as suspension goes i recommend replacing teh bushings w/ the energy suspension bushing set since they are most likely old and brittle w/ age. coilovers are a big help (which i see u already have) but make sure u have proper camber correction for them. if ur serious about drifting, a cage woudl help a lot, may as well weld one in while ur stitch welding the chassis. other common suspension parts are the strut bars and sway bars which im sure ur familiar with. there are also ladder bars and trunk bars made. also, if an ebay c pillar bar helps out a good bit and is only $30.while doing the brake upgrade u might decide to upgrade to 5 lug, either way, good tires are also essential in helping to control a drift, do some research and find out what wheel/tire combo woudl best suit ur needs and budget.as far as teh drivetrain goes, u already have an lsd, but if the cars going to be seeing a lot of track time a heavier clutch, and possibly light weight flywheel will save u a headache in the long run, also make sure the transmission is functioning properly w/ no grinding. a short shifter might increase the driving experience as well but thats personal preference. for drifting u dont need a lot of power, so engine mods arent as important as some other aspects of the car. most people at leas have basic boltons such as a downpipe, catback exhaust, intercooler, after market blow off valve, pulleys and other minor upgrades. it is important to monitor ur engine though, so a good set of gauges, a boost controller and rev limiter help. before going w/ any major engine upgrades its important to upgrade the fuel system w/ bigger injectors, fuel pump, fuel filter and fuel pressure regulator. also tuning is keep i allowing ur engine to run at its optimum potential. one very important are that is sometimes overlooked is cooling. a car that spends a lot of time getting trashed on the track will run pretty warm, and before ur engine overheats and grenades itself is ideal to upgrade the cooling system. going w/ a larger and better flowing radiator is an obvious upgrade to cooling but running electric fans and a fan controller can also have a benefit. even after u do the initial maintenance do neglect it form then on out. for instance, even if u have teh best cooling system in the world, letting the coolant get really dirty and low can cause overheating and other related issues. keep an eye on everything, especially fluids, to prevent and type of failure or problems. along the lines of cooling its also very important to let teh engine cool down as well after a hard run. either let the vehicle idle for a minute or so, or get a turbo timer for it. a turbo timer will keep the vehicle running at idle for a preset amount of time. this allows everything to cool down properly and will extend the life of ur turbo, if u have any more questions search around, but if u cant find the answers ur looking for dont be afraid to ask