or buy yourself a rb25det half cut i did for my vl however i underestimated how much it would cost me and it ended up costing me close to 8-10gs
if you turbo a r31 skyline( stock rb30) you will need to rebuild whole motor no point just slapping on a decomp plate and turbo kit cause it wont hold much boost at all. if you want information on all of it go to calaisturbo.com.au they will tell you everything yopu need to know about the rb30