Best slave and master cylinder for M5od R1 transmission

[OX644]

I have a 1991 M50D R1 in need of a new slave and master cylinder, the replacement oem stuff kicked the bucket. Now the later gen masters 1993, 1995+ and slaves are a lot different than the early gen 1991,1992.

QUESTION: What year clutch and slave for the M50d-r1 is the best design?

SPECS: I have a centerforce clutch with cheap napa master and slave in a 450 rwhp ranger with turbocharged 4.0 OHV with 422 cam, 988 springs, port and bowl work HD heads, 55lb injectors, drilled fuel rail, arp studs, felpro HD headgaskets, inline electric DV water pump, HV melling oil pump.............. list goes on endlessly, its one of the most built 4.0 OHVs.. So I want to make sure everything on the R1 is as good as it can get because Im constantly terrified of breaking it. Heres a link to my insta for the nonbelievers on the build. https://www.instagram.com/gudmundur.hjalti/?hl=en

 

[rhekman]

I have a 1991 M50D R1 in need of a new slave and master cylinder, the replacement oem stuff kicked the bucket. Now the later gen masters 1993, 1995+ and slaves are a lot different than the early gen 1991,1992.

QUESTION: What year clutch and slave for the M50d-r1 is the best design?

SPECS: I have a centerforce clutch with cheap napa master and slave in a 450 rwhp ranger with turbocharged 4.0 OHV with 422 cam, 988 springs, port and bowl work HD heads, 55lb injectors, drilled fuel rail, arp studs, felpro HD headgaskets, inline electric DV water pump, HV melling oil pump.............. list goes on endlessly, its one of the most built 4.0 OHVs.. So I want to make sure everything on the R1 is as good as it can get because Im constantly terrified of breaking it. Heres a link to my insta for the nonbelievers on the build. https://www.instagram.com/gudmundur.hjalti/?hl=en

It's unfortunate this thread didn't get more attention a month after posting. Sadly I don't really have an answer. I also have a centerforce clutch in my '95, and I'm about to install my third master/slave setup. The stock replacements just don't seem to last. I'm getting about 5 years and 50,000 miles out of each one. Not sure it's the extra pressure from the centerforce setup, or susceptibility to moisture (I had a coolant leak from the back of the intake into the bellhousing at one point).

Not a recommendation, but I just ordered & received the "standard replacement" option from RockAuto, Perfection Clutch P/N PF9055 Master & Slave prefilled assembly w/Release Bearing. https://www.rockauto.com/en/moreinfo.php?pk=1404035&cc=1138047&pt=10290&jsn=581
At least the installed release bearing appears to be a factory Sachs part (made by ZF).
My thinking was to get the whole prefilled assembly this time to avoid issues bench bleeding, incompatible or bad fluid, etc.
I can't speak to longevity, but if there are any issues after I install it this week I'll report back.

Long term I'd be interested in adapting a higher end aftermarket solution. Like if one of the concentric slaves from a T5 trans could be made to fit the M5OD-R1, or the external slave and clutch fork from the earlier Toyo-Kogyo 4 speed.