PART NO.  SPL.PAGE  DESCRIPTION                                                                
AEH593     TC.C.1    17 Tank -header -(cooling system, Twin Cam) -prior to E(131 always fit in
    additional part number AEH596 overflow pipe
ZCS0506    TC.C.1    18 Screw -tank to mounting bracket (6) -5/16-18-UNC x 3/4 hex head zinc
LWZ205     TC.C.1    19 Washer for screw (spring) (6) -Lock Washer Zinc 5/16 medium spring
AEH487     TC.C.1    20 Filler neck -(header tank, cooling system, Twin Cam)
AEH490     TC.C.1    21 Joint for filler neck -(header tank, cooling system, Twin Cam)
AEC362     TC.C.1    22 Screw for filler neck (6) -(header tank, cooling system, Twin Cam)-
    changed to PMZ0306 Com.(E)596 -always use PMZ0306
LWZ203     TC.C.1    23 Washer for screw (spring) (6) -(fill-neck, head.tank, cooling system,
    Twin Cam) -#10 medium spring split lockwasher
ARH1022    TC.C.1    24 Cap -header tank -(cooling system, Twin Cam) -changed to AHH5904-
    Com.(E)652 also 575, 613, 623, 633, 648
AEH482     TC.C.2    44 Hose -tank to thermostat housing -(cooling system, Twin Cam)
8G632      TC.C.2    45 Clip for hose (2) -(tank to thermostat housing, cooling system,
    Twin Cam) -was 2H3705
AEH575     TC.C.2    46 Bracket for header tank -(cooling system, Twin Cam)

On 5/23/2026, Bo Giersing on Twin Cam groups.io wrote:
"My YDH5 1480 resto project came with a fabricated header tank, which I intend retaining. Can't be too difficult to make if you can weld aluminum. The bracket is easy to make".

Okay, the challenge is out. Let's see if someone can whip up the design drawings to fabricate one of these from standard aluminum stock.