Reply to "water pump"

Quote- [The reason i am asking about the electric water pump is to eliminate the mechanical water pump and have a flat bulkhead. The other problem i have is moving the alternator. The only area that seems to have adequate room for this is where the aircon compressor used to be. Has any one ever done such a modification? If so photos would help.]

Ozzie, the way most flat-firewall kits work is, on post-'80s-built Panteras the alt/aircon compressor were mounted on an upgraded bracket- a smog pump was mounted above the alternator. By removing the smog pump and moving the alt up to the smog-pump mount, the alt moves up and back about an inch. This allows the alt to be driven by the unused inner sheave on the A/C compressor pulley which spins constantly when the engine is running. This then leaves only a small dimple needed to clear the water pump snout in a new bulkhead cover.
To further minimize the dimple's size, the whole powertrain can be moved backwards toward the tail about 0.650", by redrilling the hole joining the upper & lower motormounts, and bending a shallow 'S' curve in the ZF mount tabs (with new spacers). I did this a decade ago with absolutely zero problems in any respect- the exhausts were unchanged, no wires nor lines needed alterations and even the gearshift rod only needed to slide in its u-joint splines to compensate. My bulkhead 'dimple' is now roughly the size of an ashtray. All this was written up in various illustrated articles in the POCA Newsletter over around a 5 year period.
The 'convenient' powertrain move limitation is the clearance between the (removeable) rear crossmember and the notch in your (10-quart) oil pan; otherwise, the engine package could go back up to 4" with little problem. FWIW, a 4" shift backwards is routinely done in U.S big-block engine swaps, with no shortening of u-joint life. The only forseeable problem might be if someone wanted to run a 4" longer big-block engine with a 4" longer ZF 6-speed; then the A/C condenser would need to shift to the front (there are cheap commercial kits to successfully do this, too).
Your original question related to an electric water pump; I know of only one Pantera owner that has actually done this using the Mezier 55 gallon per hour pump. It works fine around town, but the engine (nearly stock) runs "a little warm" on 250-mile high speed highway trips according to the pro-mechanic owner. No idea how a high-horsepower engine on a continuous high speed open-road event like your yearly Bathurst runs would react- probably not well. I'd personally use an electric pump only to supplement the mechanical pump in this case.