If memory serves SOR had a twin tray to mount twin batts in the rear area of a 40 but have never seen one for under the hood in an 80. Thinking about it though I can not see why it would be difficult to fabricate one if needed.
I wanted to do this when I replaced my OEM with an Optima last summer. I measured and figured and measured and planned and there was no way that I could see that they would fit without some cutting of something. Maybe if they were stacked on their side or something.
Can you post pics of yours or link us to someone that has done this? I have the 2nd tray now but I would still be interested in knowing how the heck they can fit two in the stock location.
I've also been thinking about trying to squeeze two Optimas in the stock tray on my 97. There are some posts in the 80scool archives sayin' that this can be done (at least in a 91 and 92). Among some of the other concerns mentioned, I'm concern about the weight capacity of the stock tray. Can it handle twice the weight in harsh conditions? Two Optimas is a bunch of weight (82.4 lbs combined for a red top and a deep cycle blue top). Just something to ponder.