what you did is risky since they can repair the oil coolers
years ago recore was an option but if you get a recore because the core is bad odds are the coolers are just as bad and then you have a new core with old coolers that were subjected to same conditions as the core and those coolers could spring a leak and then milkshake the trans or the engine
if you need to have direct fit keeping the OE oil cooler and easy fit for transmission cooler then pony up for an alradco.
cheap route... get an Fbody radiator ..lookup 89 firebird SE(TTA) iroc etc. it doesnt have engine oil cooler so you have to get an external oil cooler or easier remove the cooler adapter from behind the oil filter (remove filter , remove nut in center , remove cooler adapter , screw filter back on . for trans just extend the trans lines with transcooler hose and clamps , and while your at it if you haven't done already you can (should consider) adding an external transcooler
while your there get the intrepid fan setup , cut the mounting ears off the sides , drop fan in use the OE fan bracket mounted at the top to hold it .. you could cut the plug from the old fan and splice it on the intrepid fans or buy a plug and play adapter but id recommend getting the racetronix hotwire kit