Perhaps I should clarify
It is only the little 18tooth and 20tooth m/s gears I have shredded; one of each. I didn't know there were two different ones, so I had to buy a third unit, thinking sooner or later I'd have two matching units. And by this time I was a bit worried, so I found a 4th unit for $50 at a swapmeet and grabbed it too. Which worked out to be a good thing, cuz some time later I ripped all the teeth off the input gear set,lol. So now I was accumulating a lotta scrap parts.
And also, as Bud mentioned, the splits in that box are horrible for a high-rpm engine.
The ratios are 3.09-1.67-1.00-.73, with splits of .54-.60-.73
What this means is at the shifts, the rpm will fall to those percents. So a hot 360 with a 292/508 cam will power peak around 5700. If you shift 1-2 at 5700, the Rs will drop to .54 x 5700 =3078. Well the 367/292combo doesn't make a lot of power down there, so your race is over. To make that split work, I had to rev it to 6800 or more, and the Rs dropped to 3672, where the engine was still lazy. The 2-3 is a bit better but not much.
To get around this, I regeared the back to put second gear where I wanted it. This took 4.88s. The second gear was now revving at 35mph=3550rpm. As you can imagine, first gear was useless, the starter gear now being 4.88 x 3.09= 15.08. So I went to 4.30s, with a starter of 13.29, still excessive.That's when I ordered the GVOD. And regeared it again, to make 1st-od my second gear. This was now 3.55s,BadaBoom; 35mph=3720. Now I had TM, Torque Multiplication.
So that's why I don't recommend that trans for a high revver.
With a slanty, where a guy rarely revs past say 4000, that 1-2 split brings the Rs down to 2160, and the slanty gets by OK.
And a stock teener, might rev to 4500, and drop to 2430,and the teener makes plenty of torque there.
But I sure wouldn't hang it on a 340, especially a low compression 340.
Your strokerBB, I'm guessing, will make mountains of low-rpm torque, so powering up from 1500 (having 1-2 shifted at 2800) will probably work just fine. It really depends on the engine build.
I like shifting at 2800 when just tooling around. My engine is very happy at 2800, and with the 3.09/direct box, the Rs drop to 1730, and my new cam (230@.050) makes plenty of torque down there.
But in the end I got tired of split-shifting that od-box.With a SBM I found that I HAD to split-shift it most of the time, and RULE #2 from GV is you cannot backshift into an OD gear. So, if I was downshifting, I couldn't get a right gear. I did learn to downshift into a regular gear and simultaneously split, but then I had to delay the clutch for the unit to be fully in-shifted before I laid on the power. It just got to be a PITA. Upshifting was excellent.
Parting thoughts;
As to installing a metal bushing in the factory aluminum box, For you that's mandatory. Even my 367 started wallering (thx to RRR for that word) out that hole.
If you value your kidneys, get the softest organic disc you can find. The CFII is a killer disc. I broke a lotta parts with that beast before I finally pulled it out. If you do use it,I suggest a driveshaft loop, or at the least a 1350 front joint. I haven't broke mine yet, and I don't think I ever will.
The factory 340 discs I bought from the local dealer don't last very long, so buy several,lol. Mostly the springspockets break spitting out the springs and then I get vibration.
I run an aluminum bell,but I wouldn't recommend that you do.
The CF PP has been a good unit for me. It currently has over 80,000 miles on it. Sometimes the flyweights stick when just cruising around,causing vibration. I just clutch it and blip the throttle and away we go.