Just an FYI, the standard battery was a 54 plate rated at 45 amp-hr with the sixes & 283, 61 amp-hr 66 plate with the larger 327s. Heavy Duty was 70 amp-hr 66 plate for all. They may have also rated them in terms of wattage, being 3200 & 4000 watts. The originals would have been Delco tar-tops through 1966 before switching to the hard rubber case Delco Eye battery for 1967.
As an FYI also, the post positions were oriented opposite between the standard vs. h.d. batteries, and the cables are different to accommodate that difference (that is if you don't want to just turn the battery around).
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67 Chevelle Malibu Sport Coupe, Oshawa-built 250 PG never disturbed.
In garage, 296 cid inline six & TH350...
Cam, Toronto.
I don't judge a man by how far he's fallen, but by how far back he bounces - Patton