with 100k miles on ur engine it may still be in great shape it may not be, decide if u want to replace it or not, possibly have it reworked, with lower compression pistons u can boost a teg safely, the problem lies in the higher compression rates of the tegs already, you can boost a teg safely with the proper setup, but ur looking at disced pistons, nice boost controllers, a good wastegate to let off excess boost pressure, new injectors to keep the gas flow up with ur increased air density. it can be done just depends on how much $$$ u want to throw into it