There was a recent discussion here about the need (actually the lack of it) for a high volume or high pressure oil pump on our mild, slow revving street engines. My concern would be shearing the pump drive shaft or rounding out the hex if using an old OEM shaft instead of a beefier, hardened aftermarket shaft. In your particular case, I can only imagine how thick your oil gets on a cold night in Alberta, putting quite a strain on that shaft when it tries to pump high-volume tar.
