69 C10 Helper bags 4"drop

[CRMW]

Hi All

I'm looking to drop the back of my C10 4"'s but I still need to use it as a truck. I'm looking at the Classic Performance Lowering Coil Springs RCS603-4 4" drop springs and I'd like to put an Air Lift 1000 Load Assist Rear Spring Kit in it however the only part number I could find when searching is the 60811 kit but I think it is for stock springs.

Does anyone know the part number for the correct kit? Or can anyone recommend another way of achieving the same results for $200 or so?

Thanks
Chris