what i normally do is just cut all the fuel pump mounting section of a fuel tank out and then weld it into the 1200 one
for this one i used a early/mid 90s magna tank as the donor as it was a bit better than the commodore tanks i normally use. has a larger opening for the fuel pump to go in so its easier to fit a larger pump and holding bracket in there, also the standard magna pump is very similar to the walbro im running, same size, outlets and electrical connector, so you can use the standard magna wiring thats in the tank and the standard magna fuel pump bracket and rubber mounting
down side is i think its sticks out of the tank a little more than a commodore one so if room is tight it might be a bit harder to fit

you can see the section i welded in at the front of this tank, and if you look closely the hole at the back where i wanted the pump to go then figured out it couldn't fit
also cut the back corner of the tank off as it made removal and installation of the tank rather difficult as you cant get to the breather lines
then i drilled out the standard feed line and put an 8mm line in to use as the return
didnt baffle the tank as its a little hard to do without cutting a really large hole in the tank, in which case i would just put a swirl pot in anyway
havent had any fuel delivery issues with it and i've had the tank down to only about 3 litres of fuel once or twice
the sedan used to starve once you got to about a quarter tank and then turned hard to the right, like in round abouts and such. this doesnt really seem to have the same problem
will be good to have the engine and stuff signed off mainly so i can start doing the rear end of the car. going to cut out and fold up the stainless for the tank today and then hopefuly get a bit of it done over the weekend and figure out where im going to run the coilovers and how im going to make the arms so that they done run into everything