small block car with big block springs?

[CamaroJesse]

i have big block 2 inch drop springs from hotchkis that i put in when i had my big block still. i now have a small block with aluminum heads. it sits just a tad too high. am i better off cutting my springs a little bit or should i buy some small block springs?

[PT_79_TA_461]

i too would like to know, i went from a 455 olds to an Aluminum Pontiac block...

[BMR Tech]

Since they are a linear rate spring and don't have flat ground ends you can cut them. The published rate on these springs is 600 lb/in which is fairly high already for a small block car. Cutting them will increase this rate too so ride quality will suffer. How is the ride now with these springs and the small block? The cheapest solution is to just try it and see if you can live with the ride....although you could probably sell an uncut set of springs so you have to factor that into the equation too!

[ROEINONDUBS]

i drove a 69 with the same set up and it was nice all we did to get the ride height where we wanted it was cut the spring with a 90 degree air cut off wheel and some antifreeze, just cut slow and only a little at a time.

[79T/Aman]

just cut the spring just make sure you cut only about half the amount you want to lower off the spring, in other words if you want to lower 1" measure the spring free length and cut off 1/2", in general this is about 1/3 to 1/2 of a coil don't worry about the increase in rate it will only be about 2-3% in other words nothing you will feel, as for cutting use a cut off wheel don't worry you wll never put enough heat in the spring to alter its properties

[CamaroJesse]

alright sounds good to me. im cuttin them!

[Buffalobillpatrick]

I cut my front BB Moog 5536 springs

Free height from 15" to 13.25" Rate went from 487# to 556#

This is about 8% per inch

CORRECT formula for
STIFFNESS OF COIL SPRING

K = W^4 x G / N x D^3

K is the Spring rate (Ib/in) I calculated 486.7# (moog 5536 table says 487#)

SO THIS FORMULA IS REAL CLOSE

W is Diameter of spring wire (in.) .687 (.687^4 = .2227547)

G is a constant of 1,406,250

.2227547 x 1,406,250 = 313,248.8

N is the Number of "free" coils (before cut was 8) (after 1.5 coil cut, which removed about 1 active coil + dead 1/2 coil) that would have been in contact with the LCA seat, so I'll use 7 active coils

D- Diameter of
spring coil (in.) 4.317 (4.317^3 = 80.453723)
center to center

313 248.8 / (7 x 80.453723) = 556#