Hi all, i've got a master cylinder on my HK 327 second type from Pagewood and its shape is the same commonly used on LJ GTRs and Xu1's -squarish top. Most if not all of the master cylinders i've seen on HK v8 Monaros are the oval shape type. Now the casting date codes on the bignut and body of my master cylinder are 20E7 and 16E7 respectively. I know the second type 327s were a bitza engine and there was a shortage of parts and my question is could my master cylinder be off a Parisienne or Impala that were being built around the same time?

That was my first thought as well. Mine has DiSC stamped as well as the date code on the Bignut. On the body there's the date code and some other code that I can't make out, although it doesn't seem to be 'Holden' stamped. All of the 1977 master cylinders I've looked at have a different lid (pitched roof type) and have FRT WHL DISC stamped on the bignut and 'Holden' stamped on the body hence my doubt and uncertaiunty.

I thought HK1837 would know the answer to my question considering the research he's done on the equivalent GM vehicles. Appreciate the reply Dr Terry and HK1837

I managed to get sometime ago the correct type master cylinder but it needs restoration. Any recommendations around Sydney area?

For a HQ type master cyl to have 20E7 & 16E7 (May 1977) date codes it would have come from the GMP&A spare parts bin.

Edited by user Saturday, 24 December 2022 7:22:53 AM(UTC)  | Reason: Not specified

I expect the nut would be the same size and thread. GMH used the HQ type m/cyl in HX production up to the end of or near the end of 1976 so GMP&A replacement m/cyls would have been made and available for many years to come.

I think there was only maybe 3 master cyls in HK. Drum, disc and that wierdo A/C one with one of the brake pipes out the front, it might have been drum only as you couldn’t get A/C with discs and V8 early on in HK. In short GTS327 won’t be any different to other disc brake HK at the same time.

That makes sense Terry. Drums and boosted drums (with the smaller booster) wouldn't have had the same clearance issue as a disc brake car did with the big Harrison compressor. Thinking back the only car I can clearly recall seeing was a Monaro coupe in Mako Blue (probably 1-2 weeks pre GTS). It was air, steer V8 and had that weird master cylinder on it. It was some sort of dealer display car as it had just about every GMH or Nasco option you could throw at a Monaro. It was fitted with the GTS's wheel covers probably before any production GTS was assembled. Possibly only the three Elizabeth GTS offline pilots (two 186S and one L34 optioned) and one online pilot each from Dandenong, Elizabeth, Acacia Ridge, Pagewood and Mosman Park (all V8 (307)) were built prior to it.

Yes I know. What I was getting at though that the Monaro I was talking had them before almost any GTS did.

No, it had the U21 option dash, ie 120mph speedo with the sports instruments.