The springs from the SBC kits can be used. There is a lot more to it than just swapping out some springs. Here's a link that I found doing a search for HEI recurving;

http://www.webrodder.com/article.php?AID=53&SID=60&CID=15

I also have a text file on a procedure to recurve the distributor to your engine. If you don't find one in your search of the web send me a pm and I'll send it to you.

Larry

Ignorance can be fixed Stupidity is forever