Why do 3rdgens have two different sized heater hoses? I didn't really notice it untill I had to replace the hoses today, but my Z28 has one 3/4" hose, and one 5/8" hose. Every other car I've seen, like my dads cars, my cousin's Galaxie 500, etc... all use two of the same size hoses. Why are 3rdgens different?

 

think you'll find very few engines, or cars with both heater hoses the same size

 

For pressure? :shrug:

 

Really?... interesting. I can't say I've ever seen one with two different ones myself. Althought I haven't really looked all that hard. I just know that the cars I have done anything with related to the cooling systems, they usually had these two hoses the same size.

Why is there two different sizes though?

 

I think it has to do with keeping a certain pressure. I cant say for sure though, as GM didnt ask me when they did it.

 

I'd think heat loss and contraction as well as 'dwell' time in the heater core. Pressure would be what the cap is on the radiator.

What were the sizes were the hose, 3/4 inlet and 5/8 exit?