Looks to be a 67 305E with cross member, you got the right parts for the conversion. One question to ask you is will you be using the 305E water pump housing rather than the one from the 478M? The 67-72 trucks are a lower profile design and in order to use a belt driven fan you will need the lower mounting 305E water pump housing which will also require eliminating the 3 piece timing gear set and replacing it with the 305,351 or 379 double roller chain & sprockets, I went through this with my 478M conversion on my 68 K2500. I wasted a lot of time on trying to modify the light duty water pump housing to accept the gear drive which ended up in failure twice and 4 hacked up housings. Finally I broke down and switched to the double roller chain drive which works just fine in the light duty application. You will have to cap of the center idler shaft hole with 1 1/8 freeze plug so no oil pressure will be lost. I'll be happy to help with advice on this conversion I've done it.
