The cell is actually on the small side. I had to fab 2 side holders, about 2 inch's wide to fill the gap. The question about assembly puzzel's me? When I recieved it , it was fully assemble. I did have to take it apart to weld an extention tube to the stock gas door location. It was very straight forward, diassembly wise. When I thought of doing this, I didn't research the NHRA rules that you have to have a steel or an aluminum barrier between the driving compartment and the fuel cell. I may have to make a shelf to contain, and or devide the driving compartment from the fuel cell. Can anybody tell me what the NHRA rules say about that. And what I can do?Thaks guys.