over heating problem

From : poo2u

Q: does it drop down to 1st if you pull the lever to 1 is anyone having the same problems. i try to keep her tuned and running ok. i have 76000 miles on her. i recently had to have the intake gasket changed and did the plenum pan as well and had the catalytic converter replaced. what im noticing now is that fast accelleration seems as if im starting out in 4th gear. big delay in take off..suggestions thanks .