OK, long story short. I had to buy new heads, the old ones were pitted so bad the machine shop couldn't machine them and keep them in spec. so I ponied up the $$ and got some refurb heads from autozone. I got the car all back together.
Somehow in torqing the upper intake, WAY before I got to torque specs (hadn't even registered 10 ftlbs yet) the back right corner bolt of the upper intake started free spinning instead of tightening. Upon further inspection I saw a corner of the LIM cracked where the bolt threaded down. How screwed am I?
However misguided the thought may have been I decided to start it up anyway so I could get some fresh oil slung around inside and flush it out a bit.
It started right up but there is a loud rhythmic popping sound. Could it possibly be a "backfire" from where the LIM and UI meet where it is cracked?