New man here. I just bought a Parts lot sale of trans parts and the trans is one I have never seen before. Has a 5th top mounting hole or ear at the bellhousing to trans area, this one is a first for me. What is it, Specs below. 1. Bellhousing- GM7 3815891 (K15) 4.11/16" has two lower pad mounts,one hole one index pin each pad. 2. Main Case-GM24 6273245 (L33), top 5th mounting hole or ear. Stamping # C4Z140469 maybe partial Vin. 3. Side Cover-GM 3952645 (L193) 25, 7 bolt cover with one center top. below cover rt. lower side stamping-S4A19. 4. Tail Housing-326558 GM56 (A84). 5. Brg Retainer-GM27 3920740 6. Input Shaft- no groves, 1.18" dia. 7. Below the 2-3 shift lever (forward one) has a TCS switch. 8. Splines- 10 front. 27 rear. 9. Tail housing has a trans/cross member mount along with end of trans has 3 tapped floor shift mounting holes. Yes I have did the Google thing with mixed answers, can any one help me with this for a RPO code or its line build #'s and or its common name? Thanks in advance.