My car developed a vibration at any speed over 65 mph. I had all the tires re-balanced and last night I tightened the front right wheel bearing. Everything else is tight. I had an alignment done last fall.
What else should I check for?

Thanks

------------------
1989 FIREBIRD FORMULA 350
K&N, ACCEL CAP & ROTOR,
FLOWMASTER AMERICAN THUNDER CAT-BACK

 

Check/replace your U-joint. If that's not the problem then you need to replace your driveshaft.

------------------
92 Camaro RS, LO3, 5-spd, T-tops

Performance:
K&N Open Air Filter, Edelbrock performer TBI intake, Fastchip Prom, Timing +4 degrees, Centerforce clutch, Xact 8mm wires, SLP 1 3/4" Headers (coated), Flowmaster Catback Exhaust, Z28 Grille w/aftmkt fog lamps, MacEwen white-face guages
Electronics:
Alpine 8030 Alarm System, Valentine One Radar Detector (How did I ever drive without one?), Pioneer DEH 7450 Head Unit w/6-pack CD changer, Pioneer DEQ 7600 Sound Processor, 2 Kenwood KAC-846 Amps powering 2 12" Pro Red subs, 2 Pioneer 6x9 and 2 MTX 4x6 speakers.
NEXT UP: TBI mods, 3.42 gears w/Torsen posi