First off i havent even desided which route i am gona go, either b16a or b18, i know i am deff gonda boost it, i am looking to put down about 270-325hp, but also need a daily driver, would it be a good idea to change the diff while i have the tranny out and all, and while i am at it which would be a better engine b16 or b18a??

 

Definitely get an LSD. No point in gettin 300HP if you can't put it down. Quaiffe is the best you can find, but only if you can afford it. I have an OEM Y1 with LSD for the type-R and it's good for daily driver. It locks at 50% slip roughly.