heavy duty or standard leaf ?

where can i see what suspension my car (1978) had ?
i see on the option list there was the option for :
RPO FE7 Gymkhana suspension ($41)
my rear spring needs to be replaced but it has only 6 leafs instead of the 7 or 9
if my car had originally the heavy duty spring leaf does that mean the front coil spring was heavy duty too.. or can a heavy duty rear leaf go well with the standard coil spring??
thankz

Quickest check is if you have a factory installed rear stabilizer. Only with the FE7 gymkhana which would have a 7 leaf spring. Standard had the 9 leaf. Mike

thankz for fast reply........ i think my car has the rear stabilizer , will check tomorrow to be certain before ordering the 7 leaf spring

Art, I know all the literature seems to say 7 leaf with gymkhana, but I had to go out and look. Both my 78SA and 79 have the FE7 but they do appear to be 6 leaf springs. Unless I'm missing something? Mike

so that probably means my 6 leaf spring is original too.. funny.. all specialists around here were wondering about my 6 leafs saying there are only 7-9 leaf springs and telling me to count again

Look at the very center of the spring. You will see a very short leaf, almost a center brace on top. That is the missing leaf. If the spring has been repaired or rebuilt in a shop it may not be there. Some set ups had a actual heavy duty brace in place of the leaf. It was still considered 7 or 9 leaf by Chevy. But keep in mind that means 7 or 9 leaf STYLE. So that's what the info says.