l dont know what turbo kit to put on my sti l have to choices

1) gt-rs (hks) turbo kit

2) t67(greddy) turbo kit

which is better and why help any suggestions
i want into 350hp to 400hp l wanna race with other cars!! like s2000 and evo is etc

Both those are decent turbo kits but they are extremely over priced compared to other kits. l would recommend either going the perrin 30r setup or 35r, you can also get the garge tuning kit which is new out there but l know the guy who designed it and it is a great turbo kit and it is cheaper than the perrin one but still makes the same power but has better spool.

why are those the only two choices?

Read on some threads on NASIOC.com and see what other people have gotten out of certain setups and then copy one that you think fits you.

You may want to look into 20g,fp green, fp red or some rotated setups.

Of those two l would take the T67

How can anyone answer ur question when u have not told them about ur goals for the car? What do u use the car for? What kind of power r u looking for. How much r u willing to spend? The two turbo is u mention r pretty big & will not only require quite the list of supporting mods but will make the car quite laggy for daily driving. l would much rather go with a stock location 30R size turbo like a GT52 or Blouch Dominator 3 for a good reliable 400 at the wheels on pump gas. If u want more, an FP red will give u more in the stock location or a rotated 35R can give u over 500 at the wheels with race gas. But without knowing wether u r building the block or what u r building the car for, l do not know which is best.