Have extra Gels and D8s. Need another battery string. Which to use?

Have two extra 109 Ah Alpha Cell gels at 75 lbs/each. Alpha owns Outback. Excellent batteries though may not be ideal for solar. New ones will cost about $250/each with shipping. Expect about 3-4 years of use...that is a wild guess.
Have two extra D8s by Johnson Controls at 125 lbs/each. These are lead acid. Big batteries for big trucks though not ideal for solar. New ones will cost about $200/each with tax. Expect about 2-3 years of use...that is a wild guess.
Seems like a real toss up to me.
Have two extra D8s by Johnson Controls at 125 lbs/each. These are lead acid. Big batteries for big trucks though not ideal for solar. New ones will cost about $200/each with tax. Expect about 2-3 years of use...that is a wild guess.
Seems like a real toss up to me.
First Bank:16 180 watt Grape Solar with FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
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So 8Ds can be alright if you get the Deep Cycle model I would think. No idea about expected longevity.
So that took me from eight 8Ds down to six. Think I will get two more and cross my fingers. 8Ds are sub par solar batteries but better than hella expensive gels I would think.