Spring Mystery

[Andy Ramm <aramm@concentric.net>]

Here's a quizical one...

Are the 7-leaf springs on a pre 74-1/2 BGT the same as on a post 74-1/2 B
Roadster?  

According to Moss, they are because they list the same part # for each.
BUT...  Brit Tek uses different part #s for these springs.  Same same or
different?  What would happen if I interchanged them?

Thanks,

Andy