CB350 frame, CB350f tank?

[Superleggera]

So picked up a nice CB350f tank for my 350 twin project the other day - I like the shape of it a lot better than the stock tank but it sits waaayyy too high on the frame as-is. Part of the problem is the mounts are in the wrong place, but the top-tube of the frame also interferes with the underside of the tank, meaning it won't be just a simple cut-and-relocate job to get it on there right. I feel like I could probably get it to sit at a reasonable height if I relocated the mounts AND hammered the tunnel down to allow extra clearence around the top-tube of the frame, but I wanted to verify whether anyone has successfully done this already. A cursory search was inconclusive, and I'd rather not hack up this tank if it won't fit in the end anyway.

 

[Mekhanic4]

I want a twin tank on my 350f. I assumed they would fit, but guess not. Not sure, hopefully someone has some insight.

 

[Superleggera]

Based on my trial of the inverse fitment, I would guess that it's going to sit a lot lower on your frame. The twin tank has a bit more breathing room between the bottom (top?) of the tunnel and the top tube on my frame, but I can't confirm that will be the same on the 4. I can, however, confirm that the length from front-to-rear mount points and front mount width are the same between both tanks.

I'll throw up some side-by-side pics.

 

[Superleggera]

Existing 350 twin tank:

350f tank:

Side by side. Note how the 350f tunnel dips down vs the relatively high and clean tunnel on the twin tank, meaning I can't just weld those mounts in higher up. This is the main issue.

On the frame.

The front of the 350f tank sits MUCH higher (note blue tape vs twin tank). I don't need to to sit AS low as the twin tank, but getting it level with the frame rails is my goal. Anybody done this successfully?

 

[Superleggera]

To answer my own question, for the archives: Yes, the tank will fit with modification. The mounts on the tank need to be cut out and welded in higher on the tank, and some fairly extensive hammering was needed to deepen the tunnel for added clearence around the top-tube. I also ground a couple mills off the tab running the length of the top-tube for additional clearence, but not enough to interfere with the spot-welds therein.

Hope this helps anyone looking to do the swap - It's a pretty good looking tank IMO.