Well if more power is needed, don’t we just add wider racing stripes ? ? I think I read somewhere that for every two inches of stripe width ( but not length ) you gain approximately 3 hp !

BTW- specialist, thanks for letting my misbehaviour of the hook. I’ll try not to be bad too often. Peace brother, let the wild turkeys fly...

Derwood.

Yeah... turns your average Mini into a stealth vehicle.

They're quieter as the thicker alloy damps out more valve train noise than the standard tinplate ones.

If you had only added racing air to the tyres, your 2.4HP would have returned. :(

From personal experience, the slanted alloy rocker cover added 2.5 hp to my Mini, but that was negated when I took off the hood stripes, so there is no noticeable hp change to be gained from this, it's visual

Oh no no darren, its ok. No offense taken. ! 
I honestly thought that anything that can be magnetized are the only ones that are conductor of electricity but anyway,, please bear with my ignorance and naughty-ness... i only hang around here more during winter because minis can only be driven during winter,  because it doesn’t overheat during winter, dare to drive your mini during summer and see what happens. 
Even in the making of the movie the Italian Job got delayed because the three minis that they used overheats so badly. Because if you analyze the sequence of where the air travels,  the air enters the front grill and touches the engine and gets extremely hot, then the radiator fan sucks that hot air from the engine and blows it directly to the radiator fan... so in essence, the radiator fan heats the radiator instead of cooling it./ and to add, the radiator does not have a drain plug..  Haaay! But we can’t blame him, he’s already dead.

Looking forward to see pics of your mini when it arrives !! Have fun!!

Quote”Darren, If you do buy one. Buy the better gasket and glue it to the valve cover. Then you can take it on and off easily. I prefer the look but some Roller Rockers don't fit under the fancy covers... Bling is nice... ”

Thanks for the tip on the gasket Debbie. I was actually wondering if gluing the best gasket I could find would be a good idea. Now I know ! And I agree, bling is good. Minis are the perfect car for adding some bling. They don’t NEED BLING, but they look good with bling. :-). Well it’s ( OMG ) almost 2a m. Off to bed and anouther day closer....

Well, there's the tip 'o the day. Be careful of the magnets in the mountains if you have a stock rocker cover.

Darren,
If you do buy one. Buy the better gasket and glue it to the valve cover.
Then you can take it on and off easily. 
I prefer the look but some Roller Rockers don't fit under the fancy covers...
Bling is nice...
Deb

Thank you all for your contributions. I have indeed learned some interesting and important things about these popular modifications. I like to give a new post some time for folks to reply before I say my thank you’s, but I think most important points about these covers have been answered. I know now that I will want to add one at some point in time, but right now I need to spend my cash on things like spare parts etc. I have placed an order, and while I admit that a few items are purely bling, most are practical, such as replacement light bulbs, breaker points, dizzy cap and rotor etc. And still more items will have to be added ( such as an extra fan belt - I think I need two, correct ? ) so that when I travel in the Mini I will have a decent supply of “ break down “ parts and tools. So thank you all once more, Best regards, Darren. PS- Specialist, I was only kidding about the electrical test on the alloy rocker covers. Please don’t try the experiment. You WILL GET A JOLT that might scare the D***ens out of you. And I don’t want that to happen. I think you know all this, but I don’t want to take your electrical knowledge for granted, and I don’t want you getting hurt. Thanks for being a good sport.

Specialist, I have to admit that you made me laugh too. But you do realize that the alloy covers are GREAT electrical conductors don’t you ? ...? One way you can prove that this alloy is non-conductive, as you say, is to pull a spark plug wire from a running Mini that has an alloy rocker cover and while holding the metal part of the spark plug wire ( put a screwdriver into the wire end if you need to ) touch the alloy cover. If you don’t feel an electrical shock, then you know for sure that the alloy is indeed a non- conductor of electricity. Specialist; please DO NOT TRY THIS EXPERIMENT IF YOU HAVE A PACEMAKER !! JUST IN CASE IT IS AN ELECTRICAL CONDUCTOR. OK ? Did I mention that I am an electronics technician by trade ? I am. Be careful. Darren.

OK, I admit it, you finally made me laugh instead of just shake my head in disbelief. 

it's lighter and it's not an electrical conductor, and if you go to mountains, it can't be magnetized by the natural magnets in the mountains.

A lot of the stock ones get over tightened and then start to leak. an Alloy one is a nice finishing touch to a detailed engine.

Looks nice....eye candy...and keeps you fit by requiring frequent repolishing with Solvol or Simichrome polish.

Some alloy rocker covers provide extra room for upgraded ratio / high lift rocker geometry. Plus they can seal with the gasket better (stamped covers can get bent and distorted).

Mostly they just look cool. 

In my quest ( thirst ) for Mini knowledge, I have sometimes wondered what the benefits ( and drawbacks ) are in using an alloy rocker cover to replace the factory pressed steel one. I think it’s very fair to say these alloy covers look better than the pressed steel units. But being alloy and having fins, they must also offer a small degree of oil cooling capacity too ( ? ). Would they also be stiffer and therefore possibly make a better seal with the cover gasket ? Do both the pressed steel unit and the alloy one use the same ( usually cork ) gasket ? So there you have it. Have I described these alloy covers properly when compared to the pressed ones ? Please tell me of anything I may be wrong about and also let me know if my notions are correct ? Opinions are also welcome in terms of value, performance, etc. Thanks to all who take the time to help me with this issue, As always, best regards, Darren.