FWIW from my limited research it looks like Chevrolet Performance offers 2 similar AC add on kits that could work with the LSA drive.
19299069 “Corvette” kit with variable displacement compressor
19244106 “LSA” kit with fixed compressor
I don’t have first hand experience with either kit, but looks promising.
I haven’t totally ruled out the Holley high mount AC bracket either, although it would certainly need to be modified. But the Holley will hold a Sanden and make an aftermarket AC install a little easier.
Hope this helps.
Holley's low mount uses the Sanden SD7B10 compressor which has a 6.1 cubic inch displacement vs the Sanden SD709 has 9.5 cubic inches (which Vintage Air recommends for the Chevelle) vs the Denso 10S17F has 10.3 cubic inches.
I sent an email to Vintage Air on the two Sanden models they offered and here's the response I received
Me - "I see that you offer 2 different low mounts for the compressor with corvette accessory spacing on an LS engine. One uses an SD 709 compressor and the other uses an SD-7B10 compressor. I noticed there’s a difference in the specs on the two (displacement/sustained revs). Does it matter which one I use for the Gen IV system in my ’67 Chevelle?"
Vintage Air - "The kit that uses the SD7B10 comp. will be when you are using a LSA engine type, for the standard LS you would use the kit that spec’s the SD709 comp.
Your correct the spec’s are pretty different, with the SD7B10 comps at idle they struggle to put out enough volume to be efficient. Generally these compressor need to be overdriven through the pulley ratios to put out good volume at idle. Now once you up in the RPM’s it will produce nicely. These are good only for systems that have a known to be overdriven.
In reality the SD 709 is larger and has a lower sustained rpm range, but it’s the better option between the two. If the sustained rpms concern you because the vehicle sees high RPM’s often, we offer a WOT cut off function on our GEN IV units so when your wide open throttle it will disengage the compressor."
Also I saw a post where someone from Vintage Air responded that the Denso 10S17F was a good choice for their systems. I was originally going with a Camaro balancer for the Maggie but am looking at running the LSA set up to give more me more flexibility for overdriving the maggie and a wider belt dedicated to the SC. For the Camaro balancer (which is the same spacing as the truck) I was using the truck setup and its version of the Denso 10S17F.