> This problem pretty much requires you to use dd to write out
> compressed tar tapes.

It is probably not worth complicating pax or tar to reblock.
As it is, one is forced to use team or ddd or something to
keep a tape streaming (especially on a PeeCee where most all
controllers limit tape blocksize to 64K or less but even
on fast SGI systems team has been very useful when you want
to use <64K size tape blocks for portability).

Bakul