I am doing a swap with a 5.3 and there is a sensor on the front top of the intake with a plastic hose/tube going to the rear, do i need this or can i disconnect it and how?

 

What year intake?

I know for 99-06 intakes "NBS", the MAP sensor is on top and the nipple with the hose going to the rear is for the rear valve cover breather/pcv dealio. There is also the brake booster hose on the very back.

 

That is your evap stuff. If you disconnect it it will just set a SES light. It injects fuel vapors from the charcoal canister at specific times, like to aid cold start and such.

 

That's evap purge solenoid just re install it on the new motor no need to do away with it as it has 0 effect on HP

 

Its an 03 5.3. Its going into a 85 chevy truck that dont have any evap crap on it and wondered what my best way to deal with it. I kind of figured it was for evap but wasnt sure how to remedy it. Any swap guys have any answers.

 

Just plug the hole like you would be deleting it no problem.