I blew a radiator hose this morn going to work on the 88 sub does anyone know how many gallons this system holds? its a 350 4x4 half ton, and what is the best proceedure for flushing out the system? Thanks much for any input.  

I little over 5 gallons. There is drain plugs on block if you want to completely drain it and start fresh. I suggest a 60/40 mix (about 3 gallons of antifreeze) and scraping the 16 PSI stock cap. It is not needed. I have run a 9 PSI cap on mine fore over 15 years now with no issues and still have original hoses on my 89 and they look like new with no swelling. Stant makes a cap for it that is for a sealed system and low pressure. (higher coolant concentration raises boil point without need for pressure cap to do it) With lower pressure leaks and hose failures are less likely and less violent when they occur.  

While it holds 5 gallons, the amount it will take completely depends on how much was lost (obviously).

The best way to flush the system is to buy a flush kit from your local autoparts store and follow the directions. It's not a hard process, but it can be messy and time consuming.  

Thanks guys, i didnt drain the engine compleatly, probably should have, but i flushed the radiator good and we're back on the road. Thanks again!  

Glad to here you got it back running!