96 chev

I was wondering if anybody had any experince or inputin the good ol reliable 4.3 v6, I just purchased a GMC Sierra(SL basic model)4x4,a month ago with a newer engine and clutch it has been running fine. I was wondering what one would go with for aftermarket parts forgetting better fuel mileage, also when I shift it into fifth it takes for ever to get from 90kmto 120km. what kind of after market parts would i go with to bump up the top end preformance? Iwastold by a mechanic that i can go as fast as i want in fourth without hurting the engine or clutchthen when i hit the speed i want shift it into 5th gear, because fith is suposedly overdrive he says. the only concern i have ismy shift indicator lights up when i am in4th and start to go past 80km. I get kind ofweary thinking Im over reving the 4th gear when this happens?

please all input would be greatly appreciated.

RhettBoeker

The shift indicator is to help you save gas milage not a true shift indicator where you must shift.