axle articulation vs spring hangar width?

[stretch67]

my question is i have a 1967 gmc longbed on a 1971 chevy frame that i mounted a 74 14 bolt ff not wanting to hack the pads off the axle to compensate for the spring perch difference i removed the perches from the donor truck and swapped the 1974 perches to my 1971 frame since the 67-72 trucks use a 2" narrower spring width[rear] do they have better axle articulation vs the 73-87 trucks?? i am planning on using my truck for limited towing so i figured the wider spring width would give me more stability and if so for 2nd gen trucks would a narrower spring perch setup help more trail flex?? /forums/images/graemlins/confused.gif

 

[BadDog]

"in-boarding" springs (particularly the rear) is a common mod to increase articulation but it comes at the expense of lateral stability. This can be somewhat offset by going stiffer which also increases the ability to carry gear but looses you some of the articulation you gained by in-boarding. Matt (NoRulz) has been very successful with his in-boarded 63” GM ¾ ton springs on a Ford F250 truggy thing…

 

[55Willy]

I read it twice but I think you have some terms missing or misused phrases.

[ QUOTE ]
not wanting to hack the pads off the axle to compensate for the spring perch difference i removed the perches from the donor truck and swapped the 1974 perches to my 1971 frame

[/ QUOTE ]
pad and perch are the same part. it's the point on the axle in which the springs are mounted.

you didn't want to remove em, but ya did??

from what I gathered you are trying to put a wider axle under the narrowe frame, but want to know if ya should move the springs out to match the wider axle mounts?

wider is more stable and narrower will flex better, but it depends on the springs and tires.

 

[ducttape114]

i run inboard 63s, they are directly under the frame rails. they flex awsome but are a little shaky on the street. lots of body roll, almost like being i a boat where your not really connected to the road. i would not tow anything, EVER. hope this helps.

 

[stretch67]

sorry i meant i used the 74 spring hangars not the perches! the 71-74 frames are the same width but i had to modify the hangars to fit the older frame bolt holes weren't the same also 67-72 use a 2" taller rear spring to gain the same lift as a 2nd gen truck so does using a spring with less arch in my case a 4" vs a 6" does this give me about the same flex i had before?

 

[BadDog]

Typically, (but not necessarily) less arch means more flex.