Update- I made a little 4 1/2" L x 3" W x 4 1/8" H mock-up and it fits in there pretty easy. A Yuasa YTZ7S would also fit. The genuine Yuasa item runs about $90 and cheap knock-offs can be had for as little as $40. If I go with this battery I'll spring for the official Yuasa item, because I'll really be pushing the limit, CCA-wise. Plus, all the Yuasa batteries I've bought over the years have been nothing short of stupendous in performance and longevity (like 7~8 years, but I would be happy with 5 years from an undersized battery).
Advantages: 6 to 7 Ah, depending on who you ask, vs. 5 Ah for the TurnTech
Much cheaper than the TurnTech
Manufacturer lists COLD Cranking amps vs. "optimal" if the temperature, humidity and phase of the moon is just right.
Proven AGM technology, never failed me
Disadvantages:Heavier than the TurnTech
Slightly bulkier, may take more finagling to get it mounted
Lower ultimate amperage, only 130 vs. 240. The Big-Crank provides 190. The Yuasa's 130 amps should work if Charon's numbers are right.
Annoying question:
"Which battery is best?"