66 poly 318 trans behind 340 in 71 Demon.

Hey guys, new to site, apologize in advance if this is long winded.
Recently purchased a 71 Demon ex /6 car. I bought it with a 69 340 backed by a 727 column shift and 8 3/4. Pulled the trans this am in preparation for a converter swap and noticed a few things. First the torque shaft for the column shifter between the frame rail and the trans case was much higher on the trans side almost into the floor seem. I goggled the trans #H2538333 and it seems it is a 1966 unit used behind a poly 318, its a B&M rebuild (based on the sticker on top of the trans) with a 26 spline input shaft. My question- is the tab on trans that the bracket bolts to higher on the early trans or is it possible I have a mix of /6-v8 parts cobbled together It seems if i would have to have a longer bracket on the frame rail side to level it out but then it would surely be hitting the floor. Second the converter I removed had a weight on it, I am sure it is a 69 340 so I should use a non weighted converter right?