COILS

[ALLZS]

way did the flat hood 69 z28 have the 293 coil & the cowl hood have the 270 coil ?

[69Z28-RS]

My understanding is that the coils themselves are the *same*, but the 'bracket' that holds them (and is associated with the part number) is the only difference..   

No, It doesn't make sense to me WHY GM did that (putting the PN? for an assembly on the part of the assembly that was the SAME, rather than on the part that was different)...   But it's been stated repeatedly by people who know so it must be true...

[70z28lt1]

The 270 coil bracket laid the coil down at a greater angle (23 degrees comes to mind) to clear the larger diameter cowl hood air cleaner housing.  The 293 coil-bracket assembly was I think 17 or 18 degrees?  Too many numbers to remember.  Anyway, generally speaking I've always heard that the coils, due to them having oil inside fro cooling the windings, should avoid be inclined in order to keep the oil inside.  Maybe that's an old hot rodders tale.

[ZLP955]

FWIW, my flat hood Z/28 has a 298 coil not a 293. The car is far from original due to being raced, but as far as I'm aware, the 298 coil is correct for flat hood Z/28.
Edit: Link to CRG Coil research thread here (couldn't find it at the time of original reply):
http://www.camaros.org/forum/index.php?topic=16716.0;all