Hi All

I have two big nut master cylinders, one has disk and one has drum stamped on the nut themselves, The one with Drum stamped on it has a VH300 cantilever Booster and the one with Disc stamped on it has a Single Diaphragm Booster, From what i have read about the boosters and Master cylinders I’m assuming that the Disc Big Nut master cylinder should go on the VH300 cantilever Booster, and Vice Versa,
There seems to be mass confusion about brake boosters and such, so here goes my questions about my boosters and Big Nuts

1. Should I put the VH300 Booster and Big Nut disc Master on my hk 307 Monaro or is it better off with a straight push type (no aircon so don’t worry about that)
2. If going the Straight push type do I keep the VH300 cantilever Booster is it worth anything or just a poor design worth nothing
3. The Vacuum Holes on the Boosters are different size; the Single Diaphragm booster has a smaller diameter hole on it than the VH300 Booster has, what is the reason behind this? Does the VH300 suck more??
4. The Big Nut Master cylinders, I know nothing about them, can someone please let me know about the difference in them are they better and such what is standard what is not and such,I also have one Big Nut with nothing stamped on it

Thank you all in advance in helping me with my Big Nut problem

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Old Holdens Can Be Restored To There Former Glory ,Wish i Could Be :(

Hi Relic_Hunter.

The Big Nut master cylinders are simply the original GM-H item for all HK/HT/HG series cars, with either disc or drum brakes (there was also an early genuine cast iron m/cyl without a nut, but these are pretty rare). The only real diff