This sounds scrumptious!  I would NEVER use that much mayo, however, ewww.  I would use maybe 1/2 cup may to the 1/2 cup sour cream.  If not creamy enough, add a bit of whole cream to the sauce before adding it to the pasta, or a little whole milk.

https://www.thespruceeats.com/bacon-ranch-pasta-salad-4799285

Sometimes I make butter noodles (those are just what they sound like - wide or extra wide egg noodles, boiled but not over-boiled, drained and rinsed, add butter *how much is up to you depending on how many noodles you make*, a bit of parsley sprinkled on, and then pre-fried bacon chopped up and sprinkled on).  Adding a bit of ranch dressing would be a great idea for this - gotta try that soon and can't believe I didn't think of it myself.  We love bacon in everything and the stuff we get from our butcher shop is just terrific, albeit expensive.  For two people it only take a couple of strips in a salad like this, but I always make a pound or more at a time and keep it in the fridge, especially in the summer.  I have some thawing right now, for that matter.