How quickly should oil pressure come up?

It seems like the oil pressure on my 318 "comes to life" later than it used too and I'm trying to decide if I should be concerned or am just worrying too much as usual. On a cold start or a warm start after sitting for an hour, it will take 2 - 3 seconds for the mechanical gage to come up with the lifters also rattling. The lifters quiet down and the gage comes up simultaneously as expected. It's a 74 318 with 46000 miles that I'm fairly sure has never had anyone in the bottom end. Pressure on a cold start at 1300 fast idle is 66 psi. Once warmed up to 180-190, the pressure at 750 is 22 with 58 going down the road at 2000 rpm. It tops out at 64psi at 3000rpm warm. I am using 10w-40 Lucas "Hot Rod Oil" and a Wix filter. A blip of the throttle at idle instantly increases the pressure. What do you guys think?
20/50W summer
10/30W when temperatures don't get above 45
That's my formula since the 70's. I use the high pressure spring with standard volume pumps both big and small blocks. Never had a problem