Does anyone know how many bolts are on the bellhouse-to-engine ba-10/5 transmission?

 

I would suggest either verifying lengths on my site or measuring out yourself, but there are two upper screws (OEM have E12 external Torx heads, but threaded 3/8"-16,) and two lower screws (standard hex heads, threaded 7/16"-14.)

Measuring for the replacements is easy - if you still have the screws, just measure from the underside of the head to the tip of the screw. If not, then measure the thickness of the flange where the screws pass through and add the nominal diameter of the screw going through it (round up to the next quarter-inch if you get a figure in between.)

Source quality screws (not Chinese!) hex heads are okeh (the "external Torx" head was developed for automated machine assembly, as they're more efficient to use than hex heads.) You may also use socket heads, or even studs (I prefer to use studs when I have room, it can make it easier to line everything up when you have more than one point of alignment to work with.)

There's a table of screw sizes on my site, linked from www.kelleyswip.com/tech.html. Feel free to submit any confirmations or new data as developed.