The 270 heads could be used if a person wanted a little more top end power and was willing to give up a little on the bottom end. I have a B-body project in my shop right now that has a 505 with TF270 heads and a 260/266 street roller cam. That engine made right at 700 hp with 650 torque peak at 4900. That guy went with 4.10 gears which are aa good match for the 270 heads, but a little steep for freeway driving. Personally I lean towards the 240 heads with 3.50 gears but if a person wants to go with the extra spicy then 270 heads and 4.10 gears will fill the bill.
I dont see any reason that the bigger ports would need that much more gear.
My 500" pump gas motor was setup extremely mild just for street cruising, it had Eddy heads that were ported to max wedge size, I ran 10.69 at 124mph driving it to and from the track with 3.23 gears. These big motors don't need 4.10 gears in my opinion.
