Looks good. Don't assume the 7 blades cools better. It doesn't. Just like extra leaf springs makes for a stiffer ride. It doesn't. Depends on other things like diameter and pitch/size of blade head. I don't think the part number was stamped on mine, perhaps a code but that doesn't help unless you know what you are looking for.
The Heavy Duty cooling with Air-Con used the 6-blade fan. #413977 (19.5")
Regular fan was the 7-blade. (19")
Does the TA have A/C or Heavy-Duty cooling originally? Or is a 79 with California smog equipment?
You can also get a heavy duty fan clutch which generally go hand in hand with the fans too. Probably wouldn't notice the difference unless one was faulty. Aftermarket replacements tend to cover many models at once so anyone's guess as to how they compared. I have the Hayden 2747 clutch which is the equivalent of the GM HD unit, of which there were several.
