"Turbo-lag" on a 22RE

I have a 91 2wd that I recently rebuilt the engine on. While I had it apart, I went ahead and opened up the intake & exhaust ports, smoothed out the intake runners, etc., basically a quick port& polish job with a Dremel. After I broke the motor in a bit, I started to try fine tuning it. The engine seems to be a bit sluggish (not bogging though) at lower RPMs, then at approx. 3500 or so gets a huge surge in power...just like it had a turbo that finally spooled up and added boost. Any suggestions on helping the low end torque situation?

I had a simmilair effect on my engine when I installed a header from lcengineering. I would feel a very noticable boost in power at exactly 3500rpms and above. Especially when traveling up hills full throttle. The proper term for the feeling you're getting is a powerband; ever rode a 2stroke bike?

did you put a header on with the new engine build or any other modifications along with the dremel job? The dremel job may have done it.

Other mods I made:
-I eliminated the Air Injection (or pulse air) system alltogether, mainly to save clutter in the engine compartment. This included capping off the air injection ports on the exhaust manifold, and removing any associated plumbing. I don't expect that had any effect on performance, but I thought it wa worth mentioning.
-I installed a drop in K& N air filter (oem replacement) and cut out a bit of the left grille area (right by the LF headlamp) to allow better air flow into the airbox.
-I eliminated the cat. conv. and installed a straight pipe in it's place. I did this mainly to avoid damaging the cat. while I sort out the correct fuel mixture adjustments in the MAF.