hemi install with Holley kit questions

I am currently in the process of dry fitting the 6.4 to my duster to make sure everything clears prior to going to paint.

I have gone the option of fitting the motor to K frame and fitting from underneath rather than dropping in.
I am finding that the drivers side header top tube is hitting the shock tower. Have other people had this issue? Should i be able to bolt together and fit from underside?
I will potentially will have the headers altered to make a perfect fit as can see motor coming in and out a few times.

I have also noticed the 02 sensors just about tough the rails when fitted what have people done to solve this?
What starter motor have you guys used if using a 727 or 904 and any mods required