340 heads on 360?

I used to have a small stack of X J U and Os, These were all very early examples and I think all were 2.02s..Without measuring them, and not actually having seen them now for over 12 years, they did look the same on the chamber side. I started selling them to stock-class racers.
I have another small stack of big-port,small-valve heads, IIRC all are Js,

For a streeter, I sure wouldn't spend money to up the valve sizes. And Why? Well if you run 3.55 street type gears, and an automatic, you won't hit 5000 until about 45 mph and she'll be spinning all the way,lol, anyway.and in about 1 second you'll be outta revs. Then you won't see 5000 again until around 75mph.