Low oil pressure hot lapping, oil cooler setup recommendations

[doridoridori]

So recently went to a drift event a week ago and at a point saw my oil pressure gauge hanging around the 8-9psi mark after hot lapping a few times coolant temps were 185-190F so not crazy hot. I let the car cool down and parked it for a while. Didn't make any noises or anything like that.

Im running an AEM oil pressure gauge so it isn't really a cheap gauge and it's pretty accurate. So I'm wondering if #1 my oil pump is starting to go out, the engine is pretty freshly rebuilt (maybe 5-6k miles on it) but the oil pump was re-used but the engine was mint and really low miles before refreshing the engine anyway. #2 the gauge sensor might be a little off but i doubt it, the gauge/sensor isn't that old or #3 i need an oil cooler.

It's a redtop SR, S14 T28 at 10psi, 550cc injectors, z32 maf.

any suggestions or help would be appreciated

also i want to get an oil cooler anyway, if anyone has any bolt on oil cooler suggestions it'd be appreciated