Re: Engine Mounts for 350/TH400
Where the big blocks are different is in the engine mount towers that bolt to the frame. These are staggered to offset the big block toward the passenger side about an inch, and the trans crossmember has about the same.
The mounts on the engine block itself aren't offset.
I think when everything is offset, the driveshaft angle is fine because it's really not that much offset. Yours sounds like the tailshaft could actually be angled toward the passenger side (crooked to the passenger side), so your driveshaft is not only seeing a trans that is offset 1", but cocked away from the pinion centerline.
I'm just chiming in because I have BB knowledge. I did drive a 350/TH400 67 in high school, and there were no driveshaft issues, but I did not do the conversion and can't recall what crossmember it had.
69 'vert project big block/TKO 600 RR
68 'vert driver RS clone -- gone!