The 3.8 60°V-6 around '04 had 8mm stems near the correct length, 1.89" int., 1.4-something exh. Wonder if They even checked into those, prob more $$$ even for stock ones.
I think the stem diameter makes more difference than might be expected. I know Justin's done some playin around with it and come up with some interesting numbers. I guess wanting to get the most flow you'd certainly look into it.
