gmc jimmy 5.7L? i have a 1989 GMC Jimmy with 350 i need a converter because me is 20 yrs old and and too rusted to hold an exhaust pipe any longer. well in the state i live in it is the for any vehicle made after 1978 you have a catalytic converter. well i have a 1981 oldmobile cutlass supreme 6 cylinder and i need to know if it will function properly on my jimmy