DUI HEI large cap distributor

Curious to see if anyone has tried to squeeze the DUI HEI distributor with large Chevy style cap in the small block A Body. DUI mentioned there needs to be a minimum of 1.5 inches from the stock cap to the fire wall. No mention about the wiper motor up top. My car 69 Barracuda is apart so I cannot check the clearance. Looks a little tight from my pre tear down pictures and from timing setting memories. Any experience out there.