340 Street Build

With 3.23s and a 2.66 low gear, yur gonna need a stout bottom end, and the ability to be able to idle along in first gear.
If yur engine won't idle down to less than 750 rpm, then, with your 235/60-14s at say 25.5 diameter, the slowest you will be able to drive, without slipping the clutch, will be ~6.2 mph. Therefore, parading is out.
Furthermore:
if you cam it for peak power at 5200, then the torque peak will come in at around 3700. Which, with 3.23s in First gear will be, ~33 mph. In other words, 33mph is where the torque peaks and the power begins ...... so below that, if the tires are not spinning, you better have a back-up plan, or you will be slipping the clutch to get there.
in my 367, I have a cam pretty much like you have. Except I run it at 10.9 Scr and close to 180 psi. My first gear is equivalent to 4.10s, and I wouldn't want to go much lower. But My engine will idle down to 550 in gear which is 4.0 mph. If I retard the timing, it will go to 500rpm/3.5 mph, and has just enough power to pull itself on flat/level/hard ground, but nothing extra to, say, climb over a dime, lol.
point being, consider how and where your combo will be driven.
I see what you mean. Now that I think about it I had that slipping the clutch issue with the Nova and the 280H cam setup. I think it was around 11.25 SCR and 205psi. Didn't want to play nice parading down the street. Also needed a rear gearing upgrade.

Just built a spreadsheet for tire ht, 1, 2, 3 and 4th gear tranny ratios along with rear gear ratios. Looks like the 235/60/14's would be ~ 25.1" tall. 750 rpm puts it at about 6.52 mph at 2.66:1 1st gear with 3.23 rear gears. 2812 rpm to get 65mph 4th gear. Thought about a 3.09 first gear kit for the tranny but would big a larger jump to the 1.91 2nd gear or switch to a set of 3.55 gears. 3.55's show about 3050 rpm at 65mph. Not a lot of mph difference at 750 rpm (5.93 mph) 1st gear with 3.55.

Think going with a little less duration on the cam might help lower the peak torque/HP band some and lower the idle rpm capability? What do you think your DCR is in that engine about 8.5ish?