[giff1]

I have a new to me 3500 express with 450 cummings 8.3 CTAs.
How much antifreeze per engine to winterize.
I will be adding the antifreeze through the sea strainers. I can't find the muffler drain plug, so I need to let the muffler fill with antifreeze too. I will be doing it in the water and the previous owner has run the exhaust hoses from the mufflers straight to the underwater exhaust. Thanks

[ReelMagic]

I have a 2003 38 Open with the same engines (6CTA 8.3) and have been winterizing them for 15 years, with the boat staying in the water for the winter.. I run 6 gallons of Non-Tox antifreeze through each engine using the raw water strainers as well.. Works for me. May be over kill but better safe than sorry. M2C

[giff1]

Anyone else know how much antifreeze for a 3500 express with Cummins.
The Mufflers look big, will 8 gallons per engine be enough?

[Lobsta]

I have a 3200 w/cummins 5.9 that i use 6 gal each engine. That has worked for me