Update for those interested.

Mine (I hope) is a very unique situation. It turns out that my motor, which was rebuilt about 20k miles ago down in SoCal was put together using pieces from many different motors, including a rear rotor housing from a TII motor. Apparently the TII motors have a different ports for coolant passages than the FD, so they had simply stuffed that hole with silicone, which, after time, started to develop a leak, and that's where my leak was coming from. Not only that, but the seals were from a 70s rotary, and they were grooves in the rotor housing, which explains why I had such weak vacuum.

What the friggin hell? Basically my motor was shoddy, and I'm actually surprised that it lasted this long.

I'm not sure if I should mention which shop I had my motor rebuilt at a few years ago, but if anybody's getting a new motor down in SoCal, PM me first. Hahahahha...

 

It's in your best interest to inform everyone of bad business like that.

The more public it's known, the less it will occur.

 

Well I did some quick searching on the forums for this place, and it looks like they get very mixed reviews. It was R&R Rotary in Upland. Again this was about three years ago, so they might have gotten better since I was there. Still...I bit bc of the price, and now I'm paying for it. Luckily I'm in SF now so I have Rick's Rotary Performance doing all the work, so I know it'll get done right and for the right price and in the right amount of time.

At R&R, my car was there for over three months!!

 

I decided to continue this thread here, where I track the installation of an Apex RX6B kit.