[TR] TR4 vs TR6 Gas Tank

[Bob]

I've been working with Boyd Welding (http://www.boydwelding.com/) on a 14 - 
15-ish gallon aluminum fuel tank for the TR6 and got to wondering if it 
would also fit the TR4. The stock tanks look the same but the TR4 tank is 
listed as unavailable. Does anyone know? BTW.... the aluminum tank price 
will be $475 which is quite a bit cheaper than the stock steel replacement 
tank. I trying to negotiate a one time group purchase so if you're 
interested email me at75TR6 at tr6.danielsonfamily.org