J-bodies and DIS

[ABTSZ]

Hi,
I am going to try and modify the system from a J-body v6 '87-'89 to work on my
car, a non-GM 6 cyl.
I've been looking thru manuals at the library and I have a few questions:
1:  I was surprised to find that ALL j-body V-6s use DIS.  From looking at the
diagrams, it seems that the DIS systems work some what on their own, and that
the only interaction with the ECM is the same as would be the case with a
7-pin HEI module.  In other words, I could do away with the DIS (which would
require a crankshaft signal) and wire it up to a HEI module, and the computer
will still function.  In other words (again) the Sync signal from the
crankshaft goes to the DIS module, but doesn't go to the ECM.  The DIS module
just sends a regular pulse to the ECM, exactly as a HEI module would.  Do you
know if this is correct?  (my car already incorporates a 4-pin HEI module so
putting in a 7-pin would be pretty much Plug-n-Play.)

2:  I could find no reference to a VATS module in any of the wiring diagrams I
saw, so maybe those models (87-89 j-body v6 w/ 7730 ECM) don't use it.  That
would be a plus!  Of course this information may be wrong, Does anybody know
otherwise?

Thanks for any info,
Adam