Front coil spring recommendations - 1968 Camaro with aluminum BBC

[GM Swiss]

Hi, I am new to this excellent forum. I am a Musclecar enthusiast from Switzerland (Lake Geneva region). A friend and myself happen to have the same "problem": A 1968 Camaro with an aluminum big block (his a ZL1, mine a KB) and needing new coil springs in the front.
The cars will mainly be street-driven, with stock, or only slightly lower than stock ride height, with occasional trackday use (no autocrossing). We are looking for a firmer than stock ride, but nothing too hard. Unfortunately, we cannot weigh the front of the (unfinished, anyway) cars. Both have aluminum radiators, and stock upper and lower a-arms.

Based on information on David Pozzi's website, I would opt for something harder than the stiffest stock spring (Z28 - 379 lbs/in), something in the 400 to 500/550 lbs/in range (Moog parts 6320 or 6041).

Your experiences and opinions would be highly appreciated here.
Thank you in advance.

[Stingr69]

The factory used a "HQ" broadcast code front spring for aluminum big block engine equipped cars.  Hard to find now for sure.  I have a set but they are unfortunately not for sale.

[janobyte]

If you could do him a solid, mic the wire diameter and count the coils/unsprung spring height. Those specs would greatly help in his search. Almost certain Mr Pozzi has the moog cross reference. Or Detroit spring could wind him a pair.

[GM Swiss]

That would be really helpful!
Thank you for your input.

[GM Swiss]

@Stingr69:
Thank you for your reply. Some vendors (Heartbeat City, Rick's/Eckler's) selling the code decals, list the code for the ZL1 spring as HG.
According to them, the HQ code would be for springs with cast iron big blocks (396, 427). What gives?
I wouldn't want you to go through the hassle of measuring your springs if the HQ spring is not the correct one.

[KurtS]

You've seen http://www.camaros.org/suspen.shtml#spring?

[Stingr69]

I got the "HQ" spring code from an article posted on this web site.   Can't confirm or deny myself it either way.  The "HQ" broadcast code appears on the broadcast sheet picture so I tend to believe it.

http://www.camaros.org/copo.shtml





The wire is 5/8" diameter

[GM Swiss]

@Stingr69:
Many thanks for the photos and the measurements!

@KurtS:
Thank you for the link. I have had a first look at the information on that page and the documents linked. I will check them out more in detail.

[janobyte]

Check out moog #6310, pozzi's website-spring chart.

[GM Swiss]

OK, thanks. Will do.

[BillOhio]

camaro spring info
http://www.pozziracing.com/camaro_spring_info.htm#SPRINGS

[GM Swiss]

Thanks. There is very good info on that page. I will quite probably use that info to decide on the springs, I am tempted to order two or three recommended part #s and experiment with them between the two cars.