No need for increased oiling. I forget where I saw years ago but it also does not seem to help with windage trays for these Mopar engines either. The biggest improvement I made to my 3.9 was to put a 3.91 gear set. I put headers and a better y-pipe on along with a cold air intake and a 50 cfm tb. It made some very nice gains.I'd like to begin a serious rebuild on a 3.9 V6 looking for a little more power. I have read the Haynes book of lies cover to cover. I have spent hours reading and looking for info on the net. It appears no one is interested in offering a camshaft or for that matter anything for the 3.9 performance wise. I'd like to hear from anyone who has raised the compression from 9.1 to 1 to say 10 to 1. I see 1.7 rockers offered and std being 1.6 I don't expect the improvement to be worth the cost. My experience with extended rockers is I gain a little top end loose some bottom end, not sure that's what I want. Current plan is a set of quality .060 pistons with file fit .065 O/S rings. Zero deck and square the block, balance assembly with new balancer , resurface flywheel w/ new ring gear and clutch. Mod the throttle body and intake manifold. Port match intake, heads and exhaust manifolds. A little bowl and port work on the heads should help. I have a compete 3 inch in and out exhaust system. If I can locate one a 4.5 qt oil pan and a oil cooler system with a thermostat. A quality timing kit and degree the cam in. A high volume oil pump and water pump. I'm sure there are some other things tried some that work some don't. I'd be interested in hearing anyway. Steve
I would not bother with intakes, cams and such because all you're doing is moving the power band up for an engine designed to move an almost 4000 lb truck. Low end torque is your friend.
If you want to rebuild the engine, I wouldn't up the compression beyond 9.5 cr. Forget MSD ignition components. The Mopar coil puts out all the spark you'll need.
The headers helped the entire power band.