Trying to ID driver side exhaust manifold

I have 2 drivers side exhaust manifolds, got them in a parts buy, they appear to be 340 driver's side upswept HP manifolds, they could be upswept 318 A body maifolds?, but the ports look rather large for 318 applications?


Sorry no pics, the casting numbers (albeit a little hard to make out properly) are: 286356 or possibly 288358 with a casting date of 12/11/8, the other manifold identical in shape however has a casting number of 2883653 and a casting date of 10/30/8

I looked at various sources trying to ID the casting numbers, no luck, anybody have a clue


Thanks
Mike

286356
288358
2883653
how clean are the numbers?
2863553

sounds like two '69 model year 340 a-body manifolds

Thanks Dan!


Casting numbers are somewhat clear, but 6's, 3's and 8's and sometimes 5"s can look like one another, plus I haven't played with smblk stuff in decades, I was pretty sure they were 340 HP castings...but the doubt is always there lol! plus I left out that extra 5 (2863553) in my post above...must be old age, again!


Thanks
Mike