have that cluster on my 87x and 8 gauge PI dash with VDOs in my other cars
senders are easy,
you'll need the 36" upper speedo cable (ebay cheap $20)
the dash bezel is going to need cutting and a plastic lens fitted (original had AVC logo in corner)
the dash carrier plastic (behind stock cluster) needs to be cut out and remove the plastic harness protector
duct behind dash needs to be drilled for a short piece of platic pipe (speedo cable runs through it)
wire for oil sender needs to be run to the oil idiot wire
wire for coolant temp ties to the OE coolant idiot wire
tach can be pulled from the analog cluster tach harness or just run a wire to the connector behind alternator
i do have the install instructs for this
issue is vdo gauges are junk and the wiring is way to tight and flimsy and have gone so far as to redo the entire harness with new spade terminals and longer wires
i have replaced nearly every gauge over the years due to issues with accuracy
tank gauges , boost gauge, speedometer , odometers , tach , water temp
all gauges except the speedo are available , for the speedo i cut the case open, repair and then weld back