it all depends on which alltrac/gt4 intercooler you have! is it the 1st,2nd or 3rd gen? the 2nd and 3rd gen are flat and square,usually black,the 1st gen is kinda irregular shaped has colors. any one can take the 9psi. but the 2nd and 3rd gen found in the 94 up gt4 or any alltrac/gt4 wrc 90 to 1993 is better can handle more boost.