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 did
n'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.