97 Z71 starting/starter problem

I have had this starter replaced 3 times and the problem is still there. The truck starts fine in the morning or after cool down, but turns over real slow and finnally starts when hot. I know it is not the starter, sooo, any ideas?

Check /test battery and cables pos. and neg. and charging system.
Run a amp draw on starter when hot.
Post back starter amp draw readings.
MT

I have had this starter replaced 3 times and the problem is still there. The truck starts fine in the morning or after cool down, but turns over real slow and finnally starts when hot. I know it is not the starter, sooo, any ideas?

this is usually a bad fuseable link....check for corrosion discoloration...i say this because of your 3 starters not changing the symptoms...i've been there done that before...not an easy find on some vehicles...