Andy, the butterfly valve with air cylinder was purchased used from a muffler shop. The controller is identical to the one used for the front wheel drive, an air switch. I also added an exhaust back pressure gauge.
As far as mods I have done over the years, here is a list:
Driven off the Camp Lejeune USMC base in NC back in 1995,
it started out as an M49A2C (196
with a N/A multifuel engine.
1)Removed the 1,200 gallon tank
2)Installed a mil spec 1975 HIAB 765 K-boom crane (from a Navy International Loadstar truck)
3) Use crane to remove winch (too much weight on front axle)
4) Built a flat bed. Used aluminum deck plate from the Loadstar
5) Flipped hubs and installed single 900's
6) Installed right angle air intake
7) Installed light bar with flood lights and "DOT" markers
Installed marker lights on front fenders and on truck bed
9) Separated rear brake lines and installed brake lock on one side. Experimented with braking one side only to help turn in mud and snow. Never finished experiments, but it did make the turn radius smaller by a few feet.
10) Installed speedo adapter for 1100's tires.
11)Installed 1100's tires
12)Converted to turbo (non-whistler)
13)Installed device to make buzzer work for turn signals
14)Installed back-up lights that work off shift lever
15)Installed "plumbing" so that axle housings could be pressurized.
16)Installed coolant filter
17)Installed alcohol evaporator
1
Installed backup alarm
19)Installed crankcase breather filter venting it just below the mushroom for recirculation of crankcase fumes
20)Installed higher air intake for fording.
21)Installed 3-station VIC-1 intercom w/CB radio
22)Installed flame heater monitoring device
23)Installed pyro and boost gauges
24)Installed "inclinometer" to check tilt while driving on side slopes
25)Installed "Bikini top" , painted it white for the cross country trip
26)Replaced home made bed with M756 pipeline truck bed
27)Installed LED type rear TTS lights
2
Started to install new military style marker lights, including blackout marker lights
29)Installed plywood custom radiator cover
30) Installed modified 25Amp regulator
31) Installed air operated exhaust brake
32) Installed headlight relay w/override switch
33) Installed relay to reduce load on turn signal flasher unit
34) Installed separate vent line for the airpak
35) Installed oil sampler valve on oil cooler
36) Installed fiberglass battery box
37) Installed dual battery maintainer/charger (years ago. It failed in a lightning storm and has not been replaced)
3 Installed radio mount and suppressor
39)Installed 24 to 12 V power supply for CB radio
40)Installed dual fuel tank system for biodiesel w/control panel
41)Installed 110VAC heating pad for batteries
42)Installed HMMWV convex mirror on passenger side.
43) Installed brake line pressure gauge
44)Installed device to monitor fuel density compensator movement
Easily shows difference in viscosity for diesel and biodiesel. Installed a gauge for it.
45) Installed a heated fuel tank system with valves and a control panel.
Top speed 62 mph
Max boost noted: 12 psi
Max fuel milage noted: 9.5 mpg.
Weight empty: 16,000 lb
Crane lift capacity: 8,250 lb 6ft out, 4,200 lb 12 ft out etc.
Crane max reach: 25 ft
Fording ready for 5 ft of water. (by plugging bell housing and pressurizing axle housings and transfer case)