sr20det refresh advice

[steve t]

hi, i have the above in my cortina and iv decided to give it a refresh with the intention of getting a bit more power, iv ordered a genuine full gasket set, i will need mains,big ends, piston rings and maybe a timing chain kit, iv not checked the head yet as i want to build the short block first, iv read that nissan parts are good quality and good to 400 horse which is about were id like to get to, so my question is which parts to get, nissan or after market, the car has the fmic which is the biggest i can get in, walbro 255 pump, 3" exhaust, apexi boost controller,k&n air filter, stock ecu with horsham 1a chip, im thinking of horsham 3a chip which is about 360 horse, cheers