Hello TJ jeepers,1st post, been following this forum for 15+ years it seems like. I need some help…First a lil background.4.0L .Jeep itself has almost 200k miles with a engine rebuild at 155k (broken piston skirt #1 cylinder). Both exhaust manifolds had small cracks and were replaced with aftermarket manifolds while service was being done. Rear manifold cracked within 1 year of daily driving and the shop replaced manifold under warranty.Material was covered labor was not. Within another year both had cracks .I preformed the repairs with the help of this forum writeups.I replaced the motor-mounts and transmission mounts as they were worn thinking the pitching and engine torque could bind and tweak the connections to exhaust. I bought what i though was standard aftermarket manifolds (Doorman) .Well guess what…rear manifold is cracked again…so heres the question…i purchased 1 set of new unboxed Mopar exhaust manifolds on ebay and 1 set of used oem Mopar exhaust manifolds on ebay with 150k miles.maybe $300.00 for both sets delivered seemed like a deal. Would you install the new ones ? Or would you install the used ones that have no visible cracks but plenty of heat cycles maybe thinking the used manifolds are seasoned? Input and reason or experience appreciated..TY
