Greetings Moparians! Havig noticed a slow increase in the volume of oil smoke at start-up, I'm inclined to suspect that the valve stem seals on the 516 heads Mathilda currently runs should be replaced. I would like to do this before Summer Solstice ideally, and pray this will suffice to keep those heads working well until I'm ready to put some well rebuilt 915s on as an upgrade. I DO NOT want to break the seal integrity of the head gaskets for any trifle! I plan to research first the best method of replacing the valve stem seals with the heads in situ, pick a good weekend for it, then do the job. I'll take compression readings Before and After as a means of quantifying success. This being said, the Question arises: Is there any brand of valve stem seal for Mopar B/RB stock heads which clearly distinguishes itself above others in quality? I currently possess a full set of Fel-Pro seals as part of a head gasket set purchased about 1 year ago, in anticipation of some head work, with the Babushka's observation of start-up fumes then. Will these suffice for the nonce, and should I use them thus: reserving the 915s for better quality valve stem seals? If so, whose product would be best? I need to start collecting parts for those 915s well matched to our purpose anyway. Hughes offers material which we deem MOST interesting and in close keeping with the design philosophy we wish to follow: plenty LOW END torque for urban driving and to best utilize the 2:76 ratio rearend on the highway. (I've NEVER had that 383 turning faster than ~4000 rpm in the 5 years we've had it, and see little point in doing so. We'll let folks with the need for that kind of performance do so with our blessing, but its not for us with this car.) Being so inclined, I suspect stock seals should do, but saw some references to silicone seals and such, which appeal to my liking for longevity. If any of you Most Learned Moparians favor a special brand/model of valve stem seal, we await your wisdom!