Moog Ft spring infoThe AMA book says the spring rates are Cutlass(336), HD(360)?, 442(435)
The installed height on our cars is 11.3"
So the free spring height, minus the installed height, x the spring rate = Load rate
To compare Moog;
Spring number....spring free height......Load height....Difference....Rate.....Load
5390....................16.80..................... ...11.3.................5.5...............336..... ..1848
5536....................15.06..................... ...11.3 ...............3.76 .............487........1831
5382.....................16.72.................... ...11.3................5.42..............360...... ..1951
5450....................15.63..................... ...11.3............... 4.33............. 450........1948
5400....................17.00..................... ...11.3................5.70..............360...... ..2052
You can see the load difference is about 100lbs per spring= 200lbs a pair.
So if you have a cutlass with a 350 motor and have 5536 and like the height, then add a 455 and ac,(+190lbs), then 5450 springs would keep the same height. Or you could just add heaver load springs to increase stance height.
:
When considering springs you need to look at the load number also. Since
the weight of the car remains constant you can adjust height with the
springs rated load and the free height. Multiplying the rated load (in
inch/pounds) by how far the spring compresses (in inches) you'll come up
with a load number in pounds
:
The GM # 402084 crosses over to the 5536 spring.

 

That is some great info, thanks for sharing!

 

This is a great reference tool also. You can sort by any column.
https://www.moog-suspension-parts.co...il_springs.asp