Trailing arm pivot point neglecting pinion angle?

[XGreen]

I have been trying to decide whether to change where I mount the front pivot point of my trailing arms. I will be welding the axle seats in after so I can set the pinion angle where ever I want. Is the only advantage of raising the pivot point to correct the pinion angle after a drop? I have done a 4" frame drop in the back for now with stock springs. I eventually may want to do a bit lower with some drop springs. Also I read somewhere that you want your trailing arms to point at the output of the trans. Why? mine are pointing under the trans output now.

Can anyone shed some light on the suspension geometry theory behind the pivot location of the front of the trailing arm suspension?
Thanks for any and all help.

[TexasLS1]

I flipped my mounting brackets when I lowered my truck to add some pinion angle back in and compensate for the drop springs (I did 5" in the rear -- 2" blocks and 3" springs). My Overall Driveline Angle came out to 1.2 degrees without shims (that's the difference between the pinion angle and the trans output shaft angle). Having the Trailing arms line up with your output shaft like you said does make sense to me as that would naturally bring pinion angle to a pretty close reflection of the output shaft angle. This was a huge reason why I decided to go through the trouble of getting out all of the freakin' rivets. It sucked with the cab and bed on the truck, but I'm glad I did it.

I read also that the steeper angle of the trailing arms helps plant the rear tires better during cornering and acceleration. Granted, raising the pivot point 3-4" likely doesn't make a huge difference, but I'm sure it is a benefit. I'm only a novice, so hopefully some of the experienced guys can chime in -- I'll try to find the Make It Handle thread where No Limit Rob explains a lot of it...

[TexasLS1]

Here is a great thread from guys who really know what they're talking about (my lame explanation was a 'water-down kool-aid' version haha). Post #9 also has a link to the 'Make it Handle' thread for more details -- http://67-72chevytrucks.com/vboard/s...d.php?t=701191 .

In my ramblings earlier, I forgot that you had made some frame modifications. Hopefully the link above will help, those guys will be able to give you good info!!