Ah, yes. White smoke and the smell of freshly burnt oil after a repair... Yep – points to a valve cover sealing problem (sorry JW).
A block of wood (a 2x4 works great), a hammer, and some (or a lot of) patience is what it takes to get those valve covers “massaged” back into shape – and is something I have to do each and every time on these engines. Take your time and do it right the first time. You should be able to eyeball a lot of the distortions, bends or outright damage to them when in the straightening mode. Having a foot long (1/3rd meter) straight edge, helps as well.
I've seen a lot of used engines that someone used chains to pull (or to install) the engine and the chains damaged the valve covers (depending on where the chains are attached). Sometimes slightly, some times massively. I've seen a lot of valve cover leaks because of that. I don't have any reason to think your engine was removed for - but saying this for other readers of our forums.
Aftermarket aluminum valve covers are nice in the fact they can keep a constant contact the entire length of the gasket – but they don't fit FMJ bodies very well, if at all.
In the early '80's, Chrysler went from using a valve cover bolt with a round captive washer
to one with a triangle shaped captive washer – which helps a lot.
For my personal cars, I will not reuse the older valve cover bolts for they bend the cover too easily.
I have a extra set which I'm sending to JW for when she gets ready to do this . . . again (sorry JW, not trying to pick on ya).
Cork gaskets might work(somewhere) – but is a very poor gasket material by today's standards. Cork is too easily damaged when tightening the bolts down – which aggregates the leakage and further distorts the valve cover.
Note: 1977 small block valve cover bolts are tightened to 40 inch/pounds (3.3 foot/pounds) – which is NOT MUCH.
1984 small block valve cover torque (which uses the triangle captive washers) is 95 inch/pounds (almost 8 foot/pounds) which is also NOT MUCH.
I recommend using a steel core (or fiber core) rubber (or silicon) valve cover gasket, which is typically more on the high end of the price range. They work better and most likely is a once and done (if working with straight valve covers), instead of doing the same job over and over.
Mopar Performance Valve Cover Gaskets this is a Mopar Performance part - which I suspect has been discontinued (but don't know for sure). There are other company's that make a similar product (and the MP part is rather pricey)
Most of the newer valve cover gaskets come with metal bushings (as mentioned above) in bolt holes to prevent one from over tightening the screws – but not all do.
BudW