C3 aux belts

[Max Cheesmar]

Hi all, I have a 71 LT1 and when the car revs to 3500 rpm it squeals like crazy, it does this in every gear. The belts I feel should be slightly tighter than they are, but the alternator belt is adjusted to the maximum so can’t be tightened.
I was wondering what the correct belt would be. I have t attached pictures of currently is there.
It is the alternator and smog pump.

Thanks.
Max

 

[Roscobbc]

Are the respective belts new? (and unstretched) - are you sure that water pump - alternator - smog pump don't have 'tight' bearings (causing the belt slip)
Presuming its a driver side alternator is its belt properly in alignment with its pulley (may not be if 'short' or 'long' water pump is applicable for your engine/year and wrong unit used and/or spacers used/not used.
Vettes from this period can develop a harmonic resonance on the long alternator bracket........and it can ultimately stress fracture. Clue will be if the bracket vibrates (badly) at certain rpm's.

 

[Max Cheesmar]

Thanks, they aren’t new i wanted to check they were the correct ones before I bought again just in case.
everything seems aligned and moving as it should.
I didnt know if they could stretch that much to be at the end of the adjustment.

 

[Roscobbc]

Thanks, they aren’t new i wanted to check they were the correct ones before I bought again just in case.
everything seems aligned and moving as it should.
I didnt know if they could stretch that much to be at the end of the adjustment.

Mines an L36 big block - I initially thought the belt set-up might be the same. Just looked in the garage......it isn't. I replaced all the belts about 3/4 years ago......mine was squealing when car was cold.....and no adjustment left. The new belts cured the issue with plenty of adjustment left. This was the first time I'd changed the belts........after 20 years of ownership!