99 yukon slt belt tensioner tapping the stopper

[rell_ent]

I upgraded my alternator to a 140 amp and replaced the belt tensioner after auto zone sold me several wrong parts. its a 1999 yukon SLT 4WD with the belt on the ac compressor. After Installment the pully tensioner will tap the stopper, it seems to get louder when put in reverse or turning the AC on. Im currently in process of ordering OEM parts to see if it will correct the issue, but and advice or help would be appreciated..

Correct part # for belt for this setup?

could the AC compressor be causing the issue?

 

[Hoesgottaeat2]

Upgrading to the bigger alternator requires a different belt. Otherwise the tensioner is maxed out. RockAuto had all options last I knew.

 

[rell_ent]

Upgrading to the bigger alternator requires a different belt. Otherwise the tensioner is maxed out. RockAuto had all options last I knew.

the belts i have put on are for 140 amps