What's it going in?
Used regular old Preston in vehicles for years that had aluminum core radiators.
I find the requirements that auto makers are placing on fluids now ridiculous. When I bought my ecodiesel ram and most people swore you had to use $10 a quart low ash euro synthetics or it would kill it, now they recommend rotella synthetic and damn near any modern diesel oil will do.
The transmission fluid costs $40 a quart and they insist you have to use that one or it wont work, yet the RAM house has a contract with Valvoline to supply the fluid they use, which is the same blend as the latest usded in the dex/merc options and can be had at Walmart for $17 a GALLON.
Hope you find what you need.