Here is an Ebay auction for a used low profile 8K Rally Pac by Ebay member "magmustangs" with a starting bid of $599.00:
1965 Ford Mustang With GT Equipment Group or Interior Decor. 1966 Ford Mustang, Fastback, Coupe, Convertible, GT. ORIGINAL LO-PROFILE RALLY PAC ASSEMBLY. With 8,000 RPM Tachometer for 289 HIPO Equipped Cars. For Use with the 5-Dial Gauge Cluster. This is an ORIGINAL FORD PART. Removed from a 66 Mustang Fastback with 289 Hipo. This Rally Pac is claimed to be rebuilt, but I cannot verify that. It is Untested by us. The wiring is cut. It does look to have some refurbishing work done to it. It looks great. Has the black krinkle finish. The tach and clock faces have great markings. No cracks or damage anywhere. Impossible To Find Original. Please email with questions. 082322-1 WE HAVE AN EBAY STORE WITH THOUSANDS OF ORIGINAL and NOS FORD PARTS. CHECK IT OUT.
1965 1966 Mustang GT ORIGINAL 8K 8000 RPM HIPO LO-PROFILE TACH - CLOCK RALLY PAC | eBay
-Fred-
This particular version is the one with 500 RPM increments. On a 6K version, that is not so bad, but I had this 8K version on one of my Kars and I found it to be a very busy dial making it hard to read, especially at night. The majority of low profile Rally Pacs are the 1K RPM increment version which works out well. I am surprised that the reproduction Rally Pacs use only this busy 500 RPM increment version.
-Fred-