Anyone use B-Body or other GM coil springs for their cars?

[jonathonar89]

Hey guys,

I was just browsing Rock Auto and found some similar springs to what we have stock on our cars but sourced under 90's B-Body (Caprice, Roadmaster, Impala SS, etc.

If I pull up '79 Firebird 400 (as example) I pretty much find two AC Delco Springs.

ACDELCO 45H0147
-Front Spring Relaxed Length       17 in.
-Load Rate Front                       2480 lbs
-Wire Diameter                               0.690 in.
-Spring Rate Front                       Constant
-Front Spring Compressed Length   10 in.
-Front Spring Inside Diameter       4.1 In.

Part # 45H0008 (Heavy Duty)
-Front Spring Relaxed Length           16.4 In.
-Load Rate Front                           2374 lbs
-Wire Diameter                                   0.710 in.
-Spring Rate Front                           Constant
-Front Spring Compressed Length   10.5 in.
-Spring Material                                   Steel
-Front Spring Inside Diameter           4.1 In.

Now if I pull up 1996 Chevy Caprice, I find very similar springs but in a higher spring rate.  Yes, these were bigger/heavier cars but the heavy duty versions of these cars were used for Taxi Cab and Police Interceptor 9C1.  The HD Caprice spring actually is almost an exact spring match for the Non-HD F-Body but at an increased spring rate.

ACDELCO 45H0001 (Heavy Duty)
-Front Spring Relaxed Length           17.1 In.
-Load Rate Front                           2900 lbs
-Wire Diameter                                   0.720 in.
-Spring Rate Front                           Constant
-Front Spring Compressed Length   10 in.
-Front Spring Inside Diameter           4.1 In.

ACDELCO 45H0115
-Front Spring Relaxed Length   18.1 In.
-Load Rate Front   2360 lbs
-Wire Diameter   0.690 in.
-Spring Rate Front   Constant
-Front Spring Compressed Length   11 in.
-Front Spring Inside Diameter   4.1 In.

Any experience or opinion on this subject?  Maybe other part #'s that come close here?  I'm just using AC Delco for cross-reference here.

[firebirdparts]

I think you’d have to cut a coil to get it down to the normal ride height with the weight of a firebird on it..  I  bet they do fit the control arms but I never had any reason to check.  I did not realize they sold springs

[jonathonar89]

I think you’d have to cut a coil to get it down to the normal ride height with the weight of a firebird on it..  I  bet they do fit the control arms but I never had any reason to check.  I did not realize they sold springs

You’re right.  1” off of each would bring it to the Firebird zone.  These are very close though.

[JJ 109]

What are you trying to accomplish?

[jonathonar89]

What are you trying to accomplish?

I was just browsing and found stiffer springs in roughly the same spec as F-Body.

The same thing can be asked about B-Body spindles.  These same cars are what many of us go to for upgrading our brake rotors to 12” 1LE rotors.  Why would we want bigger rotors that fit our stock wheels?

The B-Body also has Police interceptor/Taxi option brake pads we can install in our cars.  Those brake pads actually have more surface area than our standard D52 pads.  Why would you want to install interchangeable pads that have more area than standard?

I hope this is understandable 

[JJ 109]

 Not exactly understandable.

Want bigger brakes for better stopping power and appearance.

Stiffer spring in itself, is generally not desirable.

Most of us do it because we lower the car, and you go to higher spring rates because less travel, so we don’t bottom out.

That why I asked what you goal was, lowering, ride quality etc. otherwise it’s hard to offer an option.

If neither then use stock.

[scarebird]

I used cut down drag springs for my LS conversion - even normal springs shook your fillings out.

[JJ 109]

Cut down stock actually works well too