Dropped spindles with Truck rallys

[Leverhead]

Purchased a 'new design' CPP 2.5 standard dropped spindle kit/disk brake kit for my '64 with 15x8 truck rallys and now I'm finding they will move my wheels out 5/8-3/4 inch from drum (was told by a CPP rep they would only move out 1/16-1/4 inch). I haven't gotten a definitive answer as to why except that I may be able to send them back to swap them for modular spindles....which will move the wheel slightly in. My question is this... for anyone who has done modular from drums:

How much do they really move the wheel 'in' and is there any interference with the front suspension (lower control arms for example) using CPP modular dropped with 15X8 rallys? Thanks.

Oh....and FYI...they say that they now have modular with a 2.5 drop....