Drum Brakes pull left when hot only

[demian5]

I have a 70 c15 with coil rear.

New front linings and drums. Adjusted to duplicate drag on both (touching, then backed off just enough not to touch). Bearings are good, lubed and adjusted properly.
Front tires both at 35 PSI and rears at 32.
Had front alignment performed about 2 months ago. He did what he could and recommended upper ball joints soon.
Front suspension pretty solid. I greased all the fittings well when I did the brakes a month ago.

Rear not too old and adjusted properly about 6 months ago.

When cold, stops straight and perfect.

When hot (driven and stopped a few times) pulls to left. If a panic stop, locks up left front and will jerk wheel out of hand if not ready.

Left front wheel feels way warmer than right front after driving.

Replaced leaking booster when I first got the truck, but still has little feel of power assist.

All brake components were pretty new when I got the truck. I'm almost thinking a failing brake hose on left front.

My plan is scarebird disc brake conversion, but till then, I know I can remedy this, however I am hoping someone else out there has some insight.

I know drum brakes you need to be "prepared" when stopping, but for it to go from "man this stops great" to "@#$@$#%@# %#$@%!"... not fun...

Thanks in advance!