I had a street twin but I sold it. What was in the car was an aluminum flywheel with a McLeod disc and Long type clutch. I am using Redline MTL fluid so that could be part of the issue.
I think it is a synchro problem. When I try to shift the shifter will move out of gear easily but it feels like it hits a wall before it goes into the next gear. The shifter hangs up for a half second and then it goes into gear. I cannot shift it quickly, it just hits the wall and then after a moment it goes into gear. So the synchro is probably not spinning up to speed. Changing the fluid would be an easy fix so I'll try that.
Hey Andy, I don't think you can even buy that pressure plate any longer. At least in automotive applications. They make some for pulling trucks or something. I still use that B&B/Long cover so I know their limits.
2400 pounds of base and that disc is a parts killer. I would suggest you contact Cale Aronson at Black Magic clutches and let him update that cover. You can talk to Cale or his wife Tinzy. She is on the ball about clutches.
Cale has made his own fingers for that cover and for relatively low money he can make your cover adjustable. You won't have as much adjustment as you would with a Long style cover (I think my cover goes from 330 pounds of base to 990 and I use some counterweight to get what I think I need) but you'll at least be able to tune on it.
Some clutch shops won't deal with that cover. Cale will. I'd at least give him a call and talk to him. I think that's just too much plate load for that disc.
That won't make it shift any better, but with a sintered iron disc and that cover tuned up for adjustability you'll certainly like driving it better.
As for shifting...as the RPM and the disc weight go up and get heavier, the clutching teeth on the gears are too fine and you just can't get the slider to slid over those clutching teeth.
What I have done for years is a simple slick shifting process. And if I'm driving it on the street, I grind every other tooth off the clutching teeth on the gear and then every other tooth on the slider. I also grind every other tooth off the syncro and then assemble the transmission just like a stocker with syncros and all of it.
That, I promise you will make shifting as easy as a hot knife through butter. And the syncros will still allow up and down shifting like a stocker and you won't have to hold the shift lever and keep it in gear on decel.
I've done that for years and it's never failed to work on 833's, top loaders, Muncies and I've done a couple of Nash boxes in the early 1990's. My current car is configured like that and my wife can drive. She don't have the gonads to power shift it, but she can drive it just fine.
That's the best info I have and I hope it helps.