[455-4+1]

Ha, seems like the Muppets at Romac haven't fixed a thing in over a decade !!!
I alerted them to this problem back in 2005, they told me there was nothing wrong with the unit.

After sending them photos and CAD files of the issues, they still couldn't understand what the problem was, and then told me to just machine it so it would fit LOL (modify an SFI rated product, effectively machining off the rear retention of the out hub ????)
I suggested maybe they should have done this in the first place LOL
My initial query was below.

Have measured the hub to pully mounting face and the Romac balancer agrees with the stock one (give or take)
The main difference appears to be the width if the Romac outer ring etc which as the attached drawing shows is 0.395" further back towards the block than the stock unit
This causes it to foul on aftermarket timing covers as well as the stock timing cover and sump !!!
There is only one part number for Pontiacs (and only one required for all engies from 326-455) and this balancer will fit none of them without modifying the timing cover and sump.
What do you suggest we do ????