gas filling solution?

[gramps77]

Originally Posted by 78 Big10 454

When I bought my square new in 1978, there was no mandatory smog testing in Kommiefornia. I dumped the cat and went with straight dual exhaust and swapped out the filler neck with a model from a leaded fuel truck. That did the trick in preventing back wash every time I filled up with gas. I swap in the original non-leaded filler once every two years when I get it smogged.

Does it swap right in without issue? I was thinking of doing that, but could of sworn someone had said it wouldnt work.
I had thought of pulling mine off and having someone weld in that restrictor

Which of these would I order?
http://www.lmctruck.com/icatalog/cc/full.aspx?Page=63