74 Duster/ 5.7 swap questions

Question for you guys, as I’ve been buying parts and stuff isn’t working out well on my swap.
About my car, it started out as a 6 cylinder car. Person I got it from modified the motor mounts to work with a set made for v8 converting. They were spool style
I purchase a set of Holley mounts, but didn’t see until I went to install that they said they don’t work on a 6 cylinder kframe. So found a 71 biscuit style kframe and got it bolted in. Ordered a set of mounts I thought would work from an E body, but you guessed it, didn’t work haha.
I finally got a set of TTI motor mounts for my Duster. Got everything bolted in. Happy so far with the motor mounts, but attempted to bolt in the drivers side manifold I got from a 2015 jeep grand Cherokee, due to not wanting to drop another grand into just headers. I’ve got the engine up enough where the manifold doesn’t touch the manual steering box, but now my steering shaft is my next hurdle.
Does anyone have any recommendations on what to do or swap out to where I can connect my steering shaft to the box, as right now that big “square” part that attaches to the shaft and slips over the splined shaft of the box will not fit.