[trshman]

Let me first say I'm posting here because my '66 LeMans has a '70 GTO 400 engine with heads from a '78 TransAm.

For all the 19 years I've owned the car I've used Shell Rotella 10w-40w plus a quart of Lucas Stabilizer per my mechanic and have had no problems with my solid tappet hydraulic cam (Edelbrock Performer).

Recently reading what I'd call a "paper" evaluating over 200 oils and some additives by someone named "540 Rat" I'm now rethinking what oil to use.
This paper claims, contrary to what I've believed until now, that my engine needs the extra zinc found in the Rotella. This "540 Rat" claims that the need for zinc is wrong and that the "psi" rating and how it holds up under higher temperatures should be the only considerations (aside from cost) when choosing an oil.

Is anyone familiar with this guy or have knowledge of this report? In addition does anyone have any opinions either way about the need for zinc in an engine like mine? I'm considering either the Valvoline Full Synthetic High Mileage with MaxLife or the Quaker State Ultimate Durability because of their high "psi" ratings, how they hold up under high temps and cost with both being superior to the Rotella I've used according to his test results. I'm trying to determine if I need the ZDDPlus in addition.

Well that's my problem for today . Any thoughts/help would be appreciated.
Have a good one, trshman