my second gen is suffering from low oil pressure. at idle it seems ok but as the engine warms up the pressure works its way down to zero and never gets any higher than 50 pounds at high rpm. i have aftermarket gauges that are working properly. I recently installed a race oil pressure reg and i replaced and shimmed the front reg spring. still it never gets higher than 50. I've heard this is most likely due to a busted oring in the front cover right? i contacted a shop and they estimated $800 for the repair! well that means that i definitly want to do this myself. How hard of a job is this?

thanks