You probably already know that Novas came with 4 flavours of radiators (five if you include the minor differences on the two derv rads), but I bet you thought that the 1.6 had the biggest whilst the 1.2-1.4 had the medium and 1.0 the smallest.
Well not quite. Here's diagrams, sizes and part numbers for the Nova radiator range, including what engine they were fitted to.
Note that I've added the derv radiators for comparison. As you can see by the size and mounts, these won't fit a petrol chassis.
90136828 530 x 225 x 32mm
10S, E12GV, 12N
90136753 530 x 280 x 22mm
12ST (early), 13N/NB/S/SB (early), 14SE, C14NZ (late), 16SE, C16NZ
90298318 530 x 230 x 34mm
C12NZ, 12NV, 12ST (late), 13N/NB/S/SB (late), 14NV, C14NZ (early),
90298560 690 x 268 x 38mm
15D/DT (early)
90299108 690 x 268 x 38mm
15D/DT (late)