it should be 6.5'' round speakers
It has 4x6" speakers.
Front Door Speakers are 6-1/2"
4×6
In a 2000 chevy Silverado 1500 z71 the front door speakers are 6.5"
The front door speakers in the 2001 Silverado 1500 HD Crew Cab measure 6 3/4 inches. The rear side panel speakers measure 4 inches by 6 inches.
My 1996 Silverado Ext. Cab has 6.5" in the door panels as well as 4x6" in thee rear pillers..
The front speakers are 6.5" (round) and the back (in the extended cab doors) are the 4"x6" size.
4 x 6 rear 6-3/4 front
the ones in the door are 6.5...but depending on the speaker a 6 inch will fit too
They are 6 1/2 inch in the front door panels. If its an extended cab the rears are 4 x 6 inch. Let me tell you from experience replacing the rear speakers in a 97 extended cab is a pain, but can be done. Be cafeful not to break the panel clips then your panels will vibrate when the speakers are turned up.
the overdrive transmission in those trucks are 700R4 with lock up torque converter
The 2003 Chevrolet Silverado-1500 has a V6 engine.