What's up everyone

I have a Nissan Pickup with a Chevy 350 motor modded in it, now on park the motor is able to rev up to 4000 rpm slowly, but will not go past 3000 rpm when i stomp the pedal. It will also act the same way when i am driving it. Throttle response is ****ty and feel like it's not performing right. Does anyone know what could be the issue with it.

thanks

 

not much information but check for vacuum leaks and your timing .

 

Thanks, I'll look into it.