Hypothetical build questions…

The Isky 280 Mega is a good size street cam. Not for mileage.
(LOL)
If the OP was looking for mileage, I’d pretty much second AJ’s post and use the 360 cam with stock heads. We don’t know the level of porting his heads have. That’s why I wouldn’t use that cam.

Personally, I, myself would use a stock 340 camshaft with 1.6 rockers on his ported heads and a 3.55 gear set (Max) over the 3.73’s AJ said to use, or suggested to use. Ether way, it’ll reduce the cruise rpm a tad, have a 10.96 first gear or a 3.23 gear and have a nicer 9.98 first gear, which is closer to ideal, but the other gears are a little off. The gear spread keeps things off balance and interesting.

There’s no real right or wrong to it. Just what you want from a less than ideal gear set up. Everyone has there point of view and taste.

@vntned , are you looking for a cruising machine?
What’s the typical speed you’re traveling at?
Is interstate traveling going to be in the future with this car?
Because, the limit is 70 mph in most places, but that is mostly right lane speeds.