Correct Mike: the Cyl. & Engine doesn't know or care which way the Ports are pointed...Certainly isn't a Wedge Chamber head or even . Open squish style heads of 273 or LA318. 265's were a development from the 245ci a year or 2 later.Also came in smaller 215ci mainly for Utes (wayfarers) but suffered a bit of vibration. Apart from the 6 PAC 340 , most 340's would be hard pressed to keep up with a 2bbl bbd 265 pre lean burn to about 80-85mph: the free breathing 265 with decent Cyl Capacity 203hp version no counting the split exh warmer Can 2bbl 'Pacer' version or Same in AUST Valiant Charger went like the proverbial off a shovel. They were assembled & Exported to NZ where they were very successful on the track & Chargers Todd Motors assembled from CKD were immediate hot sellers. I've driven both & believe me even though the pre smog 340 was a hot performer a good running pedestrian 265ci L6 would still raise a few eyebrows in comparison. Discounted the Various Triple Carb versions or even the few earlier AFB equip Pacer 245ci Hemis in both 4 door Sedan or USA style 2 door Hardtop (VG Model '71) .Just Remember how those GMC 300ci got up & went Souped..
There's more than a few 265's still surviving if wanted & respond well to tuning, like the earlier Slant.
Intake valves are near overkill size std on 245ci.To throw conjuncture out there I have read the design team took their ideas from a defunct USA truck engine. Which brand was that ? & don't be fooled by tin tappet covers on side.
Cheers all.T