I believe in tune up before mod up.
Get a 180 T-stat.. top end cleaner won't hurt *unless you're in the back suckin in all the smoke
* plug and wires.. fuel filter..
Another thing is when you say it'* gutless. was the A/C on? They affect every cars performance ( IMO that I've driven mine or not )
Personal habit of mine.. if I know I will be in a rush hour stop and go traffic I turn the A/C on so both fans will run under the hood.. it doesn't help the MPG or oompah !! take off the ine.. but it'* better then walkin home or being one of those people on the side of the road with hood open and steam coming out.
I use TR55 NGK plugs..