I have just imported a dt175 1974 tank from America, and it does not fit, the tank measures 17 3/4 from front monting lug to the centre of rear mounting hole, however the frame measures 16.5 ?? Really frustrated, both my frame and engine numbers match and start at 443 019297, ive heard there was a change that year but as rare as these parts are, I cant really afford to keep spending money on what sellers claim to be the right part, is there a match and what tank do I have, please help. ??

Opsee the joys of classic ownership. It will not be the first or last time you suffer this.

Blackhat knows for certain but the a and b models look very much the same but are not. There are differences and not all of them are documented.

Like the 79 and 80 dt175. Look identical. In truth all the carb and airbox, frame, exhaust fixing, 2stroke tank as well as battery and reg unit positions changed.