Hi Mate and welcome to the Forum, First you may want to fit a pillar pod with boost and EGT guage of your choice.
then you can montor any changes in boost etc as you do mods. As for the IC you can go bigger or just get a TIG welded C/O one.
You may also want to look at fitting a Dawes valve if yours is a Di 3 ltr. EGR block is a good mod as well.Then theres the needle valve.
Plenty of time for mods, jump in anytime and ask away