1992 V6 power issue

Toyota Medallist
I have a 1992 Toyota Medallist (Limited Edition) V6. It's a real nice vehicle - all leather - full load. This year of V6, however, is notorius for low gas milage and lousy power due to a lack of ventilation both air in and exhaust out. I have just had my entire engine re-built. New block, bearings, rings, seals, timing belt etc.
I took this opportunity to re-grind the cams, install a K&N cold air induction system and Downey headers. I also ran 2.5 inch dual exhaust to the rear.
:disappoin The results have been very disappointing though. I feel that I have actually got less power now than before.She's constantly shifting down to a lower gear on the smallest of grades and she won't (never really would) hold third gear for very long. She shifts down to second, then very briefly through third to fourth and then, almost immediately back to second and the process repeats. It's a major piss off. Oh sure, she sounds tough but I feel like I'm towing a trailer all the time. I now have about 5,000 Km on my "new" motor. That should be enough break in time to loosen her up and show me her stuff - but NO .... Am I being impatient? Perhaps there's an adjustment somewhere or the timing or something simple that can be done - I've dropped a lot of dough on this project so far. Does anybody have any suggestions for me?? Or maybe a standard transmission?

regrind cams??? these engines were dogs to begin with. did you do the rebuild or someone else? does your check engine light come on when the ignition switch is on and engine not running? if so does it come on while driving? might want to check your timing marks on the cams you might be off a tooth on one of them. did you have the sub harness to the knock sensors replaced this is a must anytime the intake is removed. let us know.

Ya, dogs to be sure. The cam re-grind thing was suggested by the mechanic that did the job as part of the package to beef up this pig. The check engine light does come on when the ignition is turned on but not running and it did come on and stay on once while running shortly after the re-build. When I took it in, they told me it was a "phantom" signal - all was ok. I will check about the sub harness. Thanks so much for your suggestions - I will let you know what happens.

did you install higher compression piston in this bad boy?. if so you should have more power then before. regrinding the cams will only give you 10-20 hp if that. and on the problem you having I'm suspecting the automatic is the cause . I would opt. for a 5spd. I have a 5spd on my truck with stock motor and 2in. dual from cat back and it rocks.....

Have you tried adjusting the transmission?

Man, you're due for a transmission rebuild. You could have all the power in the world, but with a weak tranny it will run a downhill stretch like its towing. On that year of a vehicle you are definately ready to rebuild.

Thanks to all for your comments. I will have the tranny checked. Does anybody know anything about a "power chip" for the computer? Do these work? Are they cost effective?