Square Steel Stock on a 3/4 Ton Frame--Why?

[UNHLAW2016]

Good evening,
I have one that to me appears perplexing. I bought an all original 79 k20 with 25,000 mi from the fire company over the winter. I am just getting around to starting on it. From about where the frame turns up behind the cab to the beginning of the forward most rear spring hanger there appears to be a piece of I dont know 1 1/2" (The thickness of the width of the frame) square stock welded to both sides of the frame. Other than this the frame is mint, no damage, no repairs, no replaced rivets.
Any ideas?

[nonstop]

My guess would be it was some type of reinforcement for fire apparatus.

[greg64]

I'm thinking, as above, that maybe it was mounting fire equipment, not specifically to strengthen the frame. Any holes in the steel that was added?

[UNHLAW2016]

No, it is the weirdest thing.
The utility body on the truck now does not appear to be 35 years old. I am wondering if it was for U bolts maybe?
The frame looks spotless, there and everywhere
There was a pump apparatus in the back before I bought it!

[Richs'55]

Retired Firefighter. When I started on the job in 1983, we had a 1978 K20 with a pump/utility body. Nice little truck for putting out grass fires and small car fires.
It had the pump mounted right behind the cab. Power take off from the transmission would have been right ahead of that.

Suppose would need room to connect to pump and lots of fittings going in and out of that area. Along with a needing access to work on pump/fittings from below.

Post up a picture of the whole truck if you can.

[Richs'55]

Oh, also those 25,000 miles. Fire trucks are really clean because they are maintained /cleaned every day. But that engine, has probably twice as many hours than miles.
They sit a lot while pumping.

[Pine Bark Auto]

Around here, the volunteer Fire Depts used 3/4 ton trucks as "Brush Trucks". They had a small tank mounted in the bed with a pump for fighting small brush fires. I know of 2 that sustained severe frame damage due to crossing terraces and ditches with too much speed and full tanks of water. I bet many others suffered the same damage and word got around to beef up the frames. Chip.