Slipping/harsh engagement only in 4L

I've been noticing this for a while, but now that I have the transmission mounted to the engine properly and a new torque converter, it seems to have gotten worse. In 4H or 2H, it runs flawlessly with only a little bit of harshness running up the gears. Manually, 1-2,3 and D all work as expected with no slipping. I recently hot wired the Power/Comfort wires to Power just in case my switch wasn't working. No change.

What happens is I get into 4L, I have to spin the motor up to 2500 RPM and I barely move and then it engages, lurches the jeep forward and works fine from there. If I go manual 1-2, I can't even get 5mph at 5000 RPM's and it never seems to engage. I'm running 4.88's on 33's with stock 231 on an AW4. I doubt I would actually need first gear in 4L, but the hard shift and lack of any response below 2500 rpm's is concerning me.

So I noticed it again and decided to check the kickdown cable adjustment and it was already out of adjustment by 1/8" after only a couple weeks since last adjustment. The cable is frayed and catching on the adjuster clip not letting it return completely. Anyone have any luck with soldering the cable to clean it up or should I just get another one from rock auto or the junk yard since that cable is $50 new.

Another thing I noticed is I got much better gas mileage for the first tank after I replaced the torque converter. I'm wondering if a really out of adjustment kickdown cable would drink fuel too.