I think you can cut .2 off your 60 ft
No, that's not going to happen.
His problem isn't traction, which means tires and/or suspension won't make a hill of beans difference.
(And as a side note, my car has been 1.55 60's on 17" MT ET Streets with Eibach Pro Kit springs, Mach 1 shocks/struts, Bullitt sway bars front and rear, and stock everything else on the suspension. So there's really not a lot of reason to spend money on suspension parts unless you're going faster than that in the 60'.)
His problem is power. The car simply isn't making all that much anyway, and the stock tight converter is keeping it way down low in the powerband. The end result? Next to no torque going to the ground on the line, which results in slow 60's.
I fought this battle for a long time when I had the stock converter in my car. Many many many many moons ago, when I was still N/A, I was running the stock NPI heads, PI cams, PI intake, and pretty much every bolt-on available. The car ran 13.9s-14.1s @ ~99-100 every single pass it ever made like that, with about a 2.00-2.05 60' every time. I, also, was only able to swing about 1500 rpm on the footbrake before spinning. So the OP's 13.8 @ 101 sounds dead on accurate to me.
And to further illustrate the point, years later, when I had my SVO blower and really had it dialed in, I was running 11.9s @ 117-118, which is showing about 425 rwhp. Even with 425 rwhp and all the torque that a roots blower makes, with the stock converter, the car would still struggle to cut 1.80 60's. There was an occasional 1.77-1.79, but it almost always cut 1.82-1.84. You just aren't getting that much torque on the ground starting at 1500 rpm, no matter how much power the car is making. And that drastically hurts 60's, which drastically hurt 1/4 times.
To my knowledge, I've never seen a stock converter 4R70W go faster than the high 1.7s that my car cut. So I think it's safe to say that that's the absolute ceiling for a stock converter setup. And that's only with a lot of power, and a lot of low-end torque.
Now, that Circle D converter you're going to be putting in it, that's going to make a world of difference, though I'll bet when it's all said and done, you'll wish you would have gone bigger. I put a 3600 rpm converter (4c) in mine, and the 60's went from those high 1.7s I mentioned earlier to mid-high 1.5s, and the car went from running 11.9s to 11.5s. Looking back on it, wish I would have gone with a 5c.