My tach is saying the car is running at 500rpm when its actually at 1000rpm, what did everyone do about this? The tuner says he can't adjust it in the computer.

 

Check the EFI Connection website I beleive they explain there how to adjust the tables for the tach. My car isn't back up and running yet so I haven't checked mine yet also check tunedbyfrost.com, that's who I got to do my initial mailorder tune.

 

If using hp tuners, go to engine. Under general you will see tach output : high resolution and low resolution. Change those numbers to 3 .

I had the same issue when i did my swap

 

Yes. This is a PCM calibration issue. Your tuner should have no trouble with this.