To fit the stock holder in my tractor, ETX18 (340cca) from batterymart (Big Crank ETX18L Battery - Free Shipping: BatteryMart.com) or similar appears to be the best choice, at least as far as ccas go. I've read so many problems with the difficulty in starting these, my mower is an 1994 MTD. I have a new starter, but since I'm getting ready to purchase a new battery, I'm wondering if it is worth going through the trouble of rigging something to fit inside the bagging attachment under the seat area, it looks like an Everstart Group 51 (500cca) from Walmart might work. Anyway, any thoughts on whether to go through the trouble or will I be fine with the ETX18?