Re: Can I use big block stands with a 406 in my '68?
When you say the shifter hits opening slightly, where is that? On passenger side? If so, that would make some sense.
Primary thing to look for regarding 1st gen BBC vs SBC frame stands/bracket, is that, whether the 67-68 style or 69 style, the driver side is taller than passenger side. You can either just measure and post the distance from base/underside of bracket to the center of the mount through bolt. Obviously best done from aft side. Post or include the tape in pics.
If you do end up finding that your frame stands are BBC, and your trans crossmember is the SBC/L6 style, I am amazed the trans mount was even close to fitting. Should end up well forward of mount holes, unless you have one of the factory subframes that has the second set of crossmember mounting holes. Or maybe it is turned around like suggested above. Whatever.
If you do have the "wrong" crossmember but can somehow get it correctly positioned fore/aft, many guys have used the poly Energy Suspension mount that has a third, center bolt hole, and just used that one bolt through the passenger side crossmember hole. It supposedly works fine, not sure i would do it.
Lets get the engine mounting figured out, then we can talk more about the trans. Let's see the pics of what you have right now.
69 'vert project big block/TKO 600 RR
68 'vert driver RS clone -- gone!