A brief guide to the first stages of Silvia S12 Engine modification

[s12nelly16v]

any basic mods for the fj20 ?? i'm in the process of makin a straight through exhaust system , can i improve the fuel pump and injectors ! and do you have to change the oil every 2000 miles ?? i know the engine 'rattles' loads on start up is there any improvements to stop this coz it sounds painfull on start up !!! thanx for any advice !!!