Cliff's Quadrajet Parts and Rebuild Kits

Quadrajet Problem Solving => Quadrajet Parts and Numbers => Topic started by: SUPRCHY on October 05, 2025, 10:43:00 PM

Title: 4M Power Piston Spring
Post by: SUPRCHY on October 05, 2025, 10:43:00 PM

Can anyone tell me in/hg range for a 7037298 power piston spring? I've found a lot of the early spring info, but this one has eluded me.

Thanks,

-Dave

Title: Re: 4M Power Piston Spring
Post by: ourkid2000 on March 15, 2026, 07:12:14 AM

I'm interested in this as well. Could you post the info you've tracked down already? My '66 carb and my '71 service replacement both take a spring with the PN 9029922 and I don't have a clue where it lies in the stiffness ratings. I suspect it's in the middle but it would be nice to know definitively especially if you wanted to replace with a nice new one of the same spec.

Title: Re: 4M Power Piston Spring
Post by: Kenth on March 15, 2026, 02:00:17 PM

GM power piston spring (blue) #7029922 works in the 7 - 3 in/hg range.
This spring is on the "soft" side.

#7037298 was used in 1975 Olds Qjets as the auxilary power piston spring in some applications.
In other 1975 Olds Qjets the #7029922 was used as the auxilary power piston spring, so i guess they were not to far from each other.

HTH

Title: Re: 4M Power Piston Spring
Post by: ourkid2000 on March 15, 2026, 05:38:27 PM

Thanks! Helpful as always Kenth!

So if I wanted to replace my stock 7029922 with a nice new one from Cliff's kits, what would be the one to go with that matches closest? Looks like he sells a kit of 4, the blue one would be the same possibly?