I didn't know that you were building this for a 390. A factory 390 used the small 1 1/16" diameter, short snout input shaft that I posted in the pic. .
Yeah, , my son wanted to switch to a manual trans in our SBF powered drag car but I do the bulk of the wrenching and have two other car projects so that's not an option. This trans is for an old Galaxie I've been toating around since 1975
The BB tranny you found would almost be a decent match (although I like a wide ratio better.) Doesn't the Galaxie use the longer output shaft and tailhousing? A David Kee search regarding the tailshaft should give you a clue. .
The transmission I have found has thar 17" extension housing and is 31 spline
which will be correct for the Galaxie and the reason I interested in it.
Other than that, with the 390 you would have to use a 1 3/8" 428 type clutch disk, but probably in the smaller 11" diameter that will match a normal 390 flywheel if you already have one. You would also need the BB fork.
You saved me here again, It makes sense that the fork would be bigger but I
was not aware of that, I guess I would have found out the hard way.
Thanks for the information, I will have a better idea of what I'm looking at
when I go check this transmissin out, it's about an hour drive from my home, so maybe next weekend I will get out there. If I do buy it I will have questions. I hope the guy has a clutch fork!
Thank you again,