For anyone who still cares about this stuff:
Here are a couple of shots of the earlier 338's. 8.5 x 20 in front with a 245/40 and a 1" spacer.
The rear is a 20 x 10 with 275/45's and a 1.5" spacer.
I had room in the back with that set up *before* I put on the 1" spacers...But only by 1/4" before
it hit the bed on the inside edge. The ECE adjustable panhard bar allowed me to center things to
get the 1/4" even on both sides.
But the 338 folks only offered that 6.225" BS (I'm talking rear...I don't remember the front stats)
when I bought them. And, I was too far under the bed. So, at first I went with the 1" spacers in the rear.
Next was a move of the spacers to the front. And new spacers... a little wider (1.5")..... on the rear.
So, this is how she sits now with the ECE 4.5/6 drop (spindles and springs in the front, and springs in the rear....
...Not that it matters for this conversation, but a big, fat anti-sway bar up front and also ECE shock relocation
kit all around.
Oops! I forgot...The rear end is '71. That, I believe, is important. Width-wise....Just to make these stats make sense.