BB Spring Rates

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Sep 6, 2005 | 11:26 AM

danthony

Thread Starter

Burning Brakes

Joined: Aug 2005

Posts: 1,209

Likes: 86

From: Putnam county NY

2025 c3 ('68-'73) of the Year Finalist - Unmodified

2024 C3 of the Year Finalist - Unmodified

BB Spring Rates

Any idea's where I can find out what the stock sring rates are for a 1972 BB coupe, manual trans, no air.

On another note, the shocks on my coupe are too soft for my tastes, thinking about Bilstein or Koni, any opinions?

Thanks!

Sep 6, 2005 | 01:27 PM

henny496

Instructor

Joined: Dec 2004

Posts: 171

Likes: 0

From: Ontario

spring rates

Hello
I am not 100% sure on this, but I thought SB cars were 450 lbs/in and BB cars were 550 lbs/in
take care
Tom

Sep 6, 2005 | 01:37 PM

norvalwilhelm

Race Director

Joined: Nov 2000

Posts: 11,872

Likes: 12

From: Waterloo ontario Canada

Quote:

Originally Posted by henny496

Hello
I am not 100% sure on this, but I thought SB cars were 450 lbs/in and BB cars were 550 lbs/in
take care
Tom

Stock small block cars were only 280 pounds. I ran these small block springs with my bigblock and blower combination and really liked them. Big blocks are around 330 pounds and that is just a wild guess.

Sep 6, 2005 | 04:08 PM

Tom454

Le Mans Master

Joined: Apr 1999

Posts: 6,134

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From: Raleigh North Carolina

Quote:

Originally Posted by danthony

Front or Rear?

Sep 6, 2005 | 04:12 PM

norvalwilhelm

Race Director

Joined: Nov 2000

Posts: 11,872

Likes: 12

From: Waterloo ontario Canada

Production front was 280 pounds and 140 back. The F41 front was 550 and rear 305
Daytona fronts were available at 860 front and 450 back.

This is from the Chevy Power 4th edition.

Sep 6, 2005 | 05:17 PM

Wrencher

Safety Car

Joined: Oct 1999

Posts: 4,101

Likes: 10

From: NorCal

I have the F-41 on mine, and even with the weight of a all-iron 427 and A/C, it's miserable on rough roads or streets. However on smooth pavement it's awesome, as long as you watch for uneven surfaces where it tends to move around a bit under you, and takes some getting used to! A bit more compliance (or much stickier tires) in the front would be perfect.

Hans

Sep 6, 2005 | 09:18 PM

danthony

Thread Starter

Burning Brakes

Joined: Aug 2005

Posts: 1,209

Likes: 86

From: Putnam county NY

2025 c3 ('68-'73) of the Year Finalist - Unmodified

2024 C3 of the Year Finalist - Unmodified

Quote:

Originally Posted by Tom454

Front or Rear?

Both would be nice. I believe that the rear was 360 stock though.

Sep 7, 2005 | 11:24 AM

Rowdy Rat

Safety Car

Joined: Dec 1999

Posts: 3,591

Likes: 833

From: PA

Spring Rates

"danthony",

The following list of spring rates is correct for the 1968-1972 model years (there may be carry over into later years, but I am unsure of particular applications):

FRONT SPRINGS

327/350 (no A/C) - Part #3931823 - "HS" - 250 lbs/in
327/350 (with A/C) - Part #3931824 - "HT" - 264 lbs/in
427/454 (no A/C) - Part #3931825 - "HU" - 284 lbs/in
427/454 (with A/C) - Part #3931826 - "HV" - 325 lbs/in
F41 (all) - Part #3832518 - "EA" - 550 lbs/in

REAR SPRINGS

327/350/427/454 (except F41) - Part #3850839 - "EA" - 70 lbs/in (per side)
F41 (all) - Part #3828811 - "EB" - 152 lbs/in (per side)

The springs were actually chosen based on sprung curb weight, but it usually took the addition of air conditioning to require a change to the higher rate spring (which is why I listed it as "with a/c").

So, to answer your question as to what springs came on your 1972 LS-5 Corvette... "HU" (284lbs/in) front springs and "EA" (70 lbs/in per side [140 lbs/in total]) rear springs.

As for shock absorbers... Koni and Bilstein are fine choices. If you can find a set of Delco Reactec shocks you'd probably be just as happy and spend a heck of a lot less too.

Regards,