Clutch issues

[66Project]

I'm building a 2wd K5, LS 5.3 with an old school 4 speed trans.
Today my 6 year and I decided with no interior, sitting on wooden boxes no windshield or hood would pull the truck out of the shop for the first time under its on power in 2 years. It was exciting other than I couldnt put it in gear.
Dual friction clutch speedway hydraulic throwout bearing and a mid 80s C10 master cylinder. The slave cylinder instructions recommended using a 3/4 inch bore MC. The factory type GM MC is only a 11/16 bore. Im using the full stroke of the MC and the pedal feels pretty good. I was hoping it would work ok but apparently it is not. So im searching the interwebb trying to find either a replace slave or a MC that would work. Wilwood obviously makes a 3/4 inch bore but its designed to be mounted 90 degrees to the firewall. The factory one is mounted at an angle and at this point I really can't change that.
Im sure someone has had this issue before so im looking for advice on an aftermarket or factory MC that is a 3/4 bore and mounts at an angle or maybe a replacement slave cylinder. Any advice would be appreciated. Thanks

[mongocanfly]

2 thisngs I would check...make sure the system is bleed free of air...
I know on some setups the slave needs shimmed out..
which means you have to measure from both directions to determine how much you need..
also make sure the slave is making a full stroke..
what trans bellhousing setup are you using?

[66Project]

I did have troubles bleeding it at first. Found out I had a faulty MC. Swapped it out, bench bleed and evem took the trans out to remove the slave to ensure it had no way to trap air.i had a c-clamp with a block of wood in the middle to ensire I didnt over extend and confirm peddle feel. It was soild and actually compresses the wood block so I think im pretty good.
Trans is a NP440.
I ended up ordering the Wilwood today and plan on making an adapter bracket thatll put it at the right angle. Well see.

[The Ohioian]

Once I had a similar problem ended up I needed to cycle it like fifty times beat it .
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[66Project]

Well figured it out this afternoon. First I ended up getting the 3/4 MC from Wilwood and making a mount that not only changes the bolt pattern but also puts it at the correct angle. Bleed and noticed the clutch pedal feels better but still didnt release. Pull the trans and bellhouse and the clutch disc is hitting on the pressure plate bolts (ARP). Go figure. Ordered new factory GM LS bolts as from the picture the look like they have a smaller shoulder,well see.
So the factory MC probably would have been ok but now better off with the recommended bore size. Thats everyone for there help.

[mongocanfly]

Good deal..