Trans Fluid....+4?

Your car still has a converter drain plug, it was later years that they did away with it.
When it comes to types and brands of fluids you will always get a mixed bag of answers.Almost the same as what carb is better Holley or Carter you will get hundreds of answers.Either of the two fluids you mentioned will work just fine in your slant 6 904 application.Now for the 101th answer for me it's Type F with 1 quart of SAE 30 engine oil,,, That will screw with your head..........