I recently blew the MC34063A on my InkShield, but I had some MC34063Es laying around.
Unfortunately, they ran hot enough to cook and egg, and would burn out within a few minutes.
After close inspection of the InkShield schematic and the datasheet, I found that I could reduce the current draw, but keep the same output voltage by reducing the output current by a factor of about 10 (from ~400ma to ~40ma).
I replaced R1 with a 1 ohm resistor (originally 0.22 Ohm) and C2 with a 100pF capacitor (originally 1.5nF).
InkShield works again, and runs a lot cooler. I can actually hold my finger on the MC34063E now without burning myself.
Just thought I’d share, in case anyone else wanted to try a MC34063E in their InkShield.