Back shocks

nb2841 · 02-14-2013, 09:07 PM

I have a 1967 nova with a 327, it has always had a floater suspension. I am taking it to the chassis shop tomorrow to put double adj Alfco under it. It weighs 3200 with me in it. What lbs springs should I run in the back? It's a 14x32 tire car. Thanks in advance.

Tom Goldman · 02-14-2013, 10:02 PM

Assuming the shocks are behind the rear and you have an approximate axle weight of 1450# or about 45% , I'd start with a 130# spring.
I always prefer to use a lighter spring and have to load the spring to attain the proper shock center distance.

nb2841 · 02-14-2013, 10:08 PM

yes the shocks will be placed in behind the rear 9" housing. And they are 12" shocks.

SCOTT TILLEY · 02-15-2013, 07:10 AM

I have a '65 ChevyII I run in Super Stock Production with IHRA. It weighs 3030 with me in it. I use a 110 spring. Shocks are behind the rearend. I used a 95# spring for years. I thought maybe the shocks were bottoming out after talking with several racers on what spring I should be using. Turns out that I had no on track performance gain with the 110 spring. Same 60 foot of a 1.31-1.33 with a 327 2 bbl. I did notice the rear was much stiffer with the 110 riding through the pits.

Scott Tilley
IHRA SS/PDAII

curtis reed · 02-15-2013, 08:12 AM

Here is a nice little spring rate guide from Afco. I would have the chassis shop scale the car if you haven't so you would know the actual weight on the rear.

http://static.speedwaymotors.com/ima...rts/AFCOIL.gif

Larry Hill · 02-17-2013, 09:42 AM

Thanks Curtis, very good info.

02-14-2013, 09:07 PM	#1
nb2841 Junior Member Join Date: Feb 2013 Posts: 9 Likes: 0 Liked 0 Times in 0 Posts	Back shocks I have a 1967 nova with a 327, it has always had a floater suspension. I am taking it to the chassis shop tomorrow to put double adj Alfco under it. It weighs 3200 with me in it. What lbs springs should I run in the back? It's a 14x32 tire car. Thanks in advance.

02-14-2013, 10:02 PM	#2
Tom Goldman VIP Member Join Date: Jan 2003 Location: Allentown,PA Posts: 2,476 Likes: 889 Liked 882 Times in 236 Posts	Re: Back shocks Assuming the shocks are behind the rear and you have an approximate axle weight of 1450# or about 45% , I'd start with a 130# spring. I always prefer to use a lighter spring and have to load the spring to attain the proper shock center distance. __________________ Tom Goldman 1500 SG , 1506 STK

02-14-2013, 10:08 PM	#3
nb2841 Junior Member Join Date: Feb 2013 Posts: 9 Likes: 0 Liked 0 Times in 0 Posts	Re: Back shocks yes the shocks will be placed in behind the rear 9" housing. And they are 12" shocks.

02-15-2013, 07:10 AM	#4
SCOTT TILLEY Member Join Date: Jul 2006 Location: WAKE FOREST,NC Posts: 161 Likes: 90 Liked 3 Times in 3 Posts	Re: Back shocks I have a '65 ChevyII I run in Super Stock Production with IHRA. It weighs 3030 with me in it. I use a 110 spring. Shocks are behind the rearend. I used a 95# spring for years. I thought maybe the shocks were bottoming out after talking with several racers on what spring I should be using. Turns out that I had no on track performance gain with the 110 spring. Same 60 foot of a 1.31-1.33 with a 327 2 bbl. I did notice the rear was much stiffer with the 110 riding through the pits. Scott Tilley IHRA SS/PDAII

02-15-2013, 08:12 AM	#5
curtis reed Member Join Date: Jul 2011 Location: Kiefer, Ok. Posts: 167 Likes: 64 Liked 125 Times in 59 Posts	Re: Back shocks Here is a nice little spring rate guide from Afco. I would have the chassis shop scale the car if you haven't so you would know the actual weight on the rear. http://static.speedwaymotors.com/ima...rts/AFCOIL.gif

02-17-2013, 09:42 AM	#6
Larry Hill Live Reporter Join Date: Oct 2004 Location: Hickory, Ky Posts: 10,640 Likes: 1,940 Liked 10,714 Times in 2,230 Posts	Re: Back shocks Thanks Curtis, very good info. __________________ IHM Used Parts https://ihmusedparts.com 888-821-1817