Two ways for more power
I had the same need for more power. I've got a '84 280GE (automatic transmission) and routinely use it to tow and launch/retrieve my boats during the summer every weekend (I hardly use the G for anything else, in fact) -- it's the best thing on steep, slippery boat ramps.
Anyway, I did need more power because I trailer my boats back and forth every time we use them (rather than keep them in a slip); and when we vacation, we travel even farther, towing our larger boat (about 4,500 lbs incl. the trailer) a few hundred miles, sometimes much more than that, over long highway grades across New England (White and Green) Mts., or north or west across the appalachians (Adirondacks, etc.), depending where we're going.
Anyway, more power was clearly needed for those long grades. One option was installing a MB V-8 from a 560 sedan; a shop near us did that conversion routinely. I preferred to keep the project simpler, and I had a long-block custom-built (using some of my engine's parts like the flywheel and oil pan) to European sedan (280SEL) specifications, including high-compression pistons, more aggressive cam, etc. This called essentially no modifications of the engine compartment -- it looks like it's stock!
While I'm sure the V-8 alternative would have given me more torque, I'm very happy with my choice. As a reflection of my increased power, it has diminished my 0-60 times from about 17 seconds to just under 13 seconds, and from that (and using a borrowed G-Meter) I estimate I've got about 195 hp (although some on this list have estimated less than that -- not worth quibbling, though). And having enjoyed this extra power over about 3 summers of boat towing, I'm happy with this approach.
Only two downsides:
It requires more cooling -- I just had a custom, larger core radiator installed by a GWagen specialty shop near me -- we'll wait to see how much it helps this coming summer.
And it clearly needs premium fuel. It gets by with 93 most of the year, but in the hot summer when I'm pulling my boats, it really benefits from Sunoco Ultra (rated 94) -- although I don't mind, because I've always fed all my cars premium grade anyway. Alternatively, I could have detuned it with the distributor, but that would diminish the benefits of the higher compression engine, so with premium I can enjoy the full potential.
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