When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I'm needing to find a GM/DELCO/Rochester 7029529 PP spring.
Most of the PP springs I can find online don't cross reference the GM part and I have no clue what spring I need to buy to replace it. Any idea on where this opens up in Vacuum, Overall Length, # of coils? Any of this information might help me track down the right part.
From: At my Bar drinking and wrenching in Lafayette Colorado
I'm not aware of any type of cross reference spec chart or part number chart for the GM/Delco power piston springs. I have a few of the original springs that I use as "dead weight calibration springs" to select aftermarket springs to comparatively match the OEM springs. I have little drawers full of various unidentified aftermarket and OEM springs, and I dead weight test them against a known original to select a matching spring of similar tension.
The 7029529 looks like this. Note that it's a very unique spring, with tighter windings towards both ends of the spring. It was used in a lot of Pontiac carbs and Chevy truck carbs. It's fairly stiff, designed for a small cam and an engine pulling strong vacuum. It has a purple color marking (barely visible on the right half of the spring in this photo):
Specs for Rochester PP Spring
