ConwayLife.com

Here's a simple arrangement of four GGGs which runs for around 12,000 generations:
I must admit I haven't looked at many possibilities yet, but this occured to me: The highest record holder for lifespan over initial population is currently Lidka, with 2235 generations per bit. Maybe, just maybe, an exhaustive search of placements of n GGGs (IIRC, there is a 26-bit pattern which evolves into a GGG) could find a pattern which runs for over 2235*26*n generations sooner than a random soup search would.

Any thoughts?

I'm not sure if such patterns would be considered methuselahs. There are some patterns based on the switch engine that have much higher lifespan-to-initial population ratios. For example, ark 2, included with Golly, has an initial population of 19 cells and takes over 6 million generations to stabilize. This is done by having a dirty switch engine-based backrake continually hit a debris field, which is essentially the method suggested here, but has the added advantage of having the mechanism outputting the glider stream move away from the active area. The reason such patterns are not included in the methuselah list on the Life wiki is because they grow infinitely, which allows such constructions as arc 2.