I have to change the lower rad hose on my 93 gmc sierra. It is 2wd has a 350 and a 34 inch rad. My question is what is the capacity of the rad and is it alright to use the coolant already in it if it can be caught? I do have two jugs of prestone as I would need some new stuff regardless

How old is the coolant that is in there? If it is over a year, you might as well just replace it.

On my 90 K1500, I usually buy 2 gals of coolant plus 2 gals of distilled water. I use 50/50 coolant/distilled water in mine.

It won't take all of the 4 gallons but I keep a jug of what is left over (already mixed) in the back, just in case.

Don't forget to drain the overflow if you decide to replace all of the coolant.

//2000CAYukon