Good question. I had a fairly new Jeep with multi leaf springs that completely snapped on me. While on the other hand the 30+ year old monoleaf on my Nova seems to be doing a fine job to this day. Maybe they made them thicker/better. Beats me.

 

I have monos on my 67 and they are toast after about 30 runs at the track. I know others who have had the same experience. They just don't handle the stress of hard launches, slicks, traction bars, etc. Other than that I think they are better due to more flex. I will be putting in CalTrac split-leafs this weekend.

 

So lemme get this straight... for a car thats just going to be used to cruise around in, there will really be no noticeably difference between either one so i should just stick with the multi leaf?

 

leaf springs

the mono's i have on my 69 ride a lot better than the multi leafs did but supposedly there are two mono designs regular and hevy duty

 

I went 3 leaf for a 66 street cruiser. First the original monos were shot. They didn't look like it, but the car was 2" lower than factory. When I replaced the front springs and the front came up an inch or two the rear springs essentially gave up. The 3 leafs don't wrap up as much and transfer weight better under hard throttle. If they are made for the car the spring rate and ride can be the same.

 

The 3 leafs don't wrap up as much and transfer weight better under hard throttle.

Not true. Whether or not a spring "wraps up" has much more to do with its spring rate than the number of leaves. Multi-leaf springs have no inherent advantage over mono leafs. In fact, Calvert Racing does NOT reccomend using multi-leaf springs...period. They probably should know as six of the last seven champions in Stock Eliminator ran their mono leafs.
End of story.

 

I bought my mono leafs from this place for 66 Nova

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=350106205225&ssPageName=STRK:MEWAX:IT