since andy kenny and i seem to be the only resident ltslow people who post in here ill go first: (this is for the LT1 motor)
INTAKE:
Cold Air intake, some form of metal intake elbow
EXHAUST:
True duals!! mine work great, they just hit every bump
HEADS/CAM WORK:
Lt1s respond very well to even slight changes in the cylinder heads. anything from a freshen up (3-4 angle valve job, pocket port) to a full out port of the stock heads will net you great gains if matched correctly with a cam. up the lift with some 1.6 rockers and your set. i know people who have got these motors in the upward range of 7k rpms. as for aftermarket heads, afr makes some good deals ranging from like 185cfm to 225-230, also edelbrock, trickflow, and the all popular LT4 heads are available. As for cams, the most popular off the shelf cams are the lt4 hotcam and cc305 (pretty mild) to the cc306 and GM847 (heafty) a few guys like joe overton and lloyd elliot make customs that are pretty stout.
NITROUS:
the stock motor will handle a 150 shot very well. i know some guys who have up to 200 shot on a stock motor and havent broken anything yet. Depends on how well you set itup, but its probably the most popular power mod.
STROKER:
wanna go faster? this is the best way. bore and stroke for the lt1 is just like any SBC. its 350 stock, 355, 357, 377, 383, 396, and up.. forged 355 is a good route for high revving forced induction, or stroke the hell outta it for a torqu monster.
TURBO/S/C
Vortec, powerdine, and procharger are the best bets for superchargers.. there is a guy out there that made a roots setup for the lt1 which is what im going with , wouldnt go much higer than 6 lbs on the stock bottom end tho. As for turbos, STS has their rear mount and a few other companies have some turbo kits but not much due to limited engine bay space.
OTHER CRAP:
Once you start getting some decent power, the best way to get more is to increase air and fuel flow. these mods wont do much on a stock motor but will help a lot on a modded motor (heads/cam/forced induction stroker). Throttle bodys range from twin 52 all the way to monblades. other sizes are twin 54 and twin 58. Fuel injectors are a good safety mod to make sure you get the proper ammounts of fuel.. going lean sucks. SVO's are probably the cheapest. The factory maf sensor can supposedly handle 400 hp but i dont believe it. SLP, granetelli and a few other companies make bigger ones that flow better. theres other stuff too but im getting tired.
WEIGHT REDUCTION:
There is all kinds of crap you can take off these cars.. depends on how much you drive it. i drive my car every day without a/c and let me tell you its a lot easier to work on without it! ask anyone who has seen my engine bay! with all the weight reduction ive done ive dropped somewhere around 150 lbs.
well heres some stuff.. the other lt1 people will fill in the blanks