hesitation / bog down

[hayes myers]

Well... 91 200 10v... after ~30 minutes of hwy i wlil feel it start to bog
down. Flooring it does not much for a second or two...then it will 'catch'
and full boost with throttle mashed. let off and revs fall off like it's
going to die.  Downshift..rev it out and then it is ok again (seems fixed).
This has happened at excactly the same time period 3 times in last 2 weeks.
It is disconcerting when this happens... feels like it wants to die on the
hwy...then it runs fine.

Anyone with similar issue?
ty
Hayes