The CCI pop-up/ reserve gas tanks fit the V-Twin rigid frame ok, except for the bottom tank mount, which hits the top of the Pan cover, which it does on two sets of OEM tanks, so the frames wrong.
The CCI 3.5 tanks are wider in the back, like fatbobs, and just look wrong. Boo!!! A total disappointment. CCI tried to cover both Pan and Shovel's by offering only one set of tanks and the tanks look more Shovel than Pan. The OEM style gas line isn't going to fit either, but the crossover tube can be sweated out of the banjo fitting and a new steel line brazed. Seems like I got a replacement crossover line with the tanks and I thought back then that it seemed wider than usual - Just some more on-the-spot-discoveries, making my way through a Panhead build.
Note: V-Twins replica Knuckle gas tanks, w/o emblem mounts (38-0140) have a drawn-in tank at the back like OE. (I'll post a comparison pic later). They look good, but I've heard the petcock placement is out of place for the '37-47 stock crossover lines too.
Looks like I can grind the bottom off the tank mount (to above the yellow line) and still be able to fasten both tank halves to the frame mount. The frame mount also hit the Pan cover earlier, but I ground some of it away to make room. Once these tanks are mounted, I can move on to wiring the A, B, and C main wiring harness. I'll post some pics later.
The bottom, front, jiffy stand nut won't fit between the back of a V-Twin cast frame mount for the jiffy stand and the frame rail. It's suppose to use a lockwasher too, but forget about the lockwasher. No room. Grind the nut on one side (or find a thin profile jam-nut), and it fits okay in the nook that's provided.
OEM tank is on the right. CCI on the left. They made the rear of the tank too wide. Proof, that if you don't actually own a Panhead....don't try and make parts for something you don't understand.
It's 3-1/2" from the bottom tank mount to the center of the petcock on the OEM tank.
It's 4" from the bottom tank mount to the center of the petcock on the CCI. That's what keeps the stock style fuel line from making the reach to the left tank. Does anyone else make OHV tanks that are more real than these "fit-all's"? I don't think so.