6, and see how it rides. If you are racing it, then loosen the fts to, say 3, and the rears left at 6. Video the launch, and look for tire spin. Looser shocks will hit the tires harder.
Loose in ft will allow for more/faster pitch rotation.
I bought mine, the singles were all that was available. I got low 1.4's w/ them, at 3700#.
I used the HR bar, the QA's, my own uppers/lowers, stock springs. [I also had them on the ft, w/ Moroso BBC springs.]
I'd think if it's an occasional visit, the singles would be a big help.