Holley-which secondary spring - The 1947 - Present Chevrolet & GMC Truck Message Board Network

johnwaynejeep · 07-20-2017, 12:07 AM

I'm replacing my QJet with a Holley 4160 (1850-2). I need help in choosing the correct spring for the vacuum secondary diaphragm to make sure they open at the right time. I have a 75 C10 short bed flare side. The title says the weight is 3050. I think the real weight is more like 3750.

Is there a chart to cross reference vehicle weight with the diaphragm spring?

Thanks
Robert

BTW, I've had great luck with the Qjet and I plan to rebuild the Qjet and have it on the backburner ready to install.

geezer#99 · 07-20-2017, 09:07 AM

THe tried and true method is your 'buttometer'!!
Go one step at a time weaker on the springs until you get a bog then go back one spring.
Btw your truck likely is pushing closer to 4200 lbs.

johnwaynejeep · 07-20-2017, 12:37 PM

sounds good. thanks

Titomars · 07-20-2017, 03:22 PM

Assuming you have a S/B and it is fairly stock try starting with the long yellow spring. You will probably find that to be the best overall. My 75 El Camino with a 350 likes that spring best. I am running an 1850-1. secondary spring tuning is based on WOT, rpm range, car weight and gears.

07-20-2017, 12:07 AM	#1
johnwaynejeep Registered User Join Date: Jul 2014 Location: Pacific Grove, CA Posts: 105	Holley-which secondary spring I'm replacing my QJet with a Holley 4160 (1850-2). I need help in choosing the correct spring for the vacuum secondary diaphragm to make sure they open at the right time. I have a 75 C10 short bed flare side. The title says the weight is 3050. I think the real weight is more like 3750. Is there a chart to cross reference vehicle weight with the diaphragm spring? Thanks Robert BTW, I've had great luck with the Qjet and I plan to rebuild the Qjet and have it on the backburner ready to install. __________________ Robert 1975 C10 - Huckleberry 2007 Jeep JK - John Wayne Jeep Smittybilt front/rear bumper, 10K winch Pacific Grove, CA

07-20-2017, 09:07 AM	#2
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,512	Re: Holley-which secondary spring THe tried and true method is your 'buttometer'!! Go one step at a time weaker on the springs until you get a bog then go back one spring. Btw your truck likely is pushing closer to 4200 lbs.

07-20-2017, 12:37 PM	#3
johnwaynejeep Registered User Join Date: Jul 2014 Location: Pacific Grove, CA Posts: 105	Re: Holley-which secondary spring sounds good. thanks __________________ Robert 1975 C10 - Huckleberry 2007 Jeep JK - John Wayne Jeep Smittybilt front/rear bumper, 10K winch Pacific Grove, CA

07-20-2017, 03:22 PM	#4
Titomars Registered User Join Date: Feb 2015 Location: Santa Rosa, Ca. Posts: 539	Re: Holley-which secondary spring Assuming you have a S/B and it is fairly stock try starting with the long yellow spring. You will probably find that to be the best overall. My 75 El Camino with a 350 likes that spring best. I am running an 1850-1. secondary spring tuning is based on WOT, rpm range, car weight and gears. __________________ 1977 Chevrolet C/10 Silverado. Step-Side, Factory 454, TH400, 3.73 Posi 12 Bolt. 1975 Chevrolet El Camino. 350, TH400, 3.08 Posi 10 Bolt.



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.