Sound like they are 8" 250lbs, my standard springs i think were 8" 275lbs, i could not get the drop i wanted with the 7.5" wide rims, the bottom collars where so close to the tyres it meant using spacers, instead i got some spring from James which were only 6" long, that slammed the bitch.
Its going to be down to the wheel clearance on the front Andy, you are going to have to just look at, willy wheels will probably be ok.
Give me a buzz if you want a chat about doing the torsion bars, its a pig of a job getting them out but dead easy to set up and refit