Wow, what a question for a new visitor! I certainly do not profess to be an expert (rather new myself), but I feel your pain, after spending seemingly countless hours earlier in the year looking for basically the same answers. In my case for L-35 conv., but affected by much the same issues.
I will attempt to lay out the rationale for what I eventually concluded. Likely this may prompt some disagreement and/or corrections, but here goes anyway...
The 1967 AIM references on this
(front: pg #3-A7) (rear: pg #4-B1), are
VERY VERY CONFUSING to begin with.
The charts cited by Jim & Kurt above are very helpful in trying to clarify the AIM references, but still not a silver bullet.
Supplementing these, I also referred to the downloadable OPTIONS CHART at
http://www.camaros.org/options.shtml#RPOSpreadsheetKEY ASSUMPTIONS: A) #396; B) CONVERTIBLE. This allows one to eliminate small-blocks & L-6's & coupes from the myriad A.I.M. options...
Starting with the
REAR SPRINGS:1) The CRG paper at
http://www.camaros.org/suspen.shtml (paragraph 3) notes;
"All 1967 models used monoleaf design rear springs." Hold that thought...
2) The service parts listing '67springs.jpg' (pictured above) notes (last line) "WITH SPEC. SPRING EQUIP." 3912554 (coupe) and 3920220 (Conv).
3) Referring back to A.I.M. (pg #4-B1): these part numbers appear to correspond to RPO option
G31.
4) "G31" appears in the AIM 49 times (text search). It is defined in
only one place (Index page A1) as "Spring-Rr-Spc (See UPC 4)".
5) Referring to the OPTIONS.PDF spreadsheet: G31 is described as "Springs,
special multi-leaf rear (incl rear bumper guards)."
Quantity produced for 1967 = NONE. THis is consistent with point #1 above (from the white paper).
6) So, going back to the Service Parts Listing: After eliminating #3920220: For either L-35 or L-78, you are left with only #3909941 (BJ). The A.I.M. indicates this part is used in both L-35 and L-78 applications.
7) The A.I.M. does list several other part#s (#3909940 for one), but the Service Parts Listing supports this only for 327-2V applications (not for #396). I have heard of this appearing on actual cars.... maybe used on the production line, but not used as a service part for #396 cars? not sure...?
#8) In my case, had one more bit of evidence:
SPRING TAG PHOTOS taken when the car was disassembled!
#3909941 (BJ) 9) There is much discussed elsewhere on the site about spring identification by paint stripes and color codes. Thankfully I did not need to concern myself with this, having the original spring tags.
FRONT SPRINGS:10) The Service Parts Listing indicates ONLY #3912544 (YK) for #396 convertible (all).
11) The Front Spring table (67_front_springs.jpg) appears to agree.
12) And also the A.I.M. agrees as well (pg. #3-A7)
13)
SPOILER: The A.I.M. front spring table (at top) calls for code colors
"BLACK ON RED". I have come to learn the colors generally used were
WHITE ON BLUE, this is discussed elsewhere on the site. ECS offers a red/black version (not perfect but it exists). Don't believe the
WHITE ON BLUE is offerred anywhere.
14) If we were talking about a COUPE; I'm not sure how you would distinguish YG and YJ applications. Thankfully, for CONVERTIBLE I did not need to concern myself with this.
DISCLAIMER: As stated above, the available documentation is very confusing, so this is my attempt to best use it to address the question at hand. And as always, other variables such as production sequence, timing, and pure anomalies may also factor in (potentially derailing my 'thesis').
HOPE THIS HELPS...
