Flipping trailing arm mounting brackets?

[Hart_Rod]

Here's how I did mine, . The sawsall, air chisel and punch made this a pretty simple job. I also have some rear end pinion shims just in case this doesn't fix all the angle mismatch. After reading everything here, I "assume" I should put them in to help rotate the pinion up in the front???? Also, another advantage seems to be that it pushed my rear wheels back approximately an inch, which helps better center them in the wheel well.

[gringoloco]

Looks good, Rob Any clearance issues, either at the floor cross-sills or where the arms pass under the frame? Also, have you re-installed the driveshaft? Since it moved you back an inch, any issues at the trans yoke?

[lolife99]

Rob,... just curious how this mod pushed the rearend back 1"?

Is the ECE crossmember located in a different set of frame holes?

[SCOTI]

Originally Posted by lolife99

Rob,... just curious how this mod pushed the rearend back 1"?Is the ECE crossmember located in a different set of frame holes?

The ECE x-member mounts in the OE location unless it's modified/moved by the installer.

The rear end on a T/A set-up swings up & forward on its natural arc as it gets lower. By raising the pivot point in front, it's like you're not lowering it as much in the rear as it swings through the arc of travel.

As we know, the lower the truck, the farther forward in the wheel opening the axle C/L shifts. Not being as low in the arc should mean the rear end sits slightly farther back & yields positive pinion angles.

[lolife99]

I see the 6" drop spring and a 2" block moving the rearend forward.
I just don't see the bracket flip moving it rearward as much as 1 inch.
(with the pivot point being the coil spring)

I do see the advantage of gaining a better pinion angle.

[Hart_Rod]

Originally Posted by lolife99

I see the 6" drop spring and a 2" block moving the rearend forward.
I just don't see the bracket flip moving it rearward as much as 1 inch.
(with the pivot point being the coil spring)

I do see the advantage of gaining a better pinion angle.

I don't know that it's exactly 1", I just kinda swagged it, . I do know visually it has moved back... When I get it back on the ground I'll see if I can get a before and after picture.

[SCOTI]

Originally Posted by lolife99

I see the 6" drop spring and a 2" block moving the rearend forward.
I just don't see the bracket flip moving it rearward as much as 1 inch.
(with the pivot point being the coil spring)I do see the advantage of gaining a better pinion angle.

Which is why I stated this.....

Originally Posted by SCOTI

Not being as low in the arc should mean the rear end sits slightly farther back & yields positive pinion angles.

I feel that 1" measurement is unlikely, but it will move it back.

[scrapmetalart]

how low is too low to do this? I have 5" rear springs & am adding 2" blocks & might go to 6" springs...will this cause a clearance issue with the bed?

[72gmcshorty]

Is this crossmember flip recommended for someone with a mild c-notch, airbags, shock relocators?

[WAAF]

silly question, hope is doesn't highjack the o/p thread..
I understand the flip of factory bracket= cheap and easy
but,(always the but)
would making or useing mount like they use on a 4 link set up.. with 4 mounting points.. allow you to tune the rear set up more?
or is this overkill on this.

[SCOTI]

Originally Posted by WAAF

silly question, hope is doesn't highjack the o/p thread..
I understand the flip of factory bracket= cheap and easy
but,(always the but)
would making or useing mount like they use on a 4 link set up.. with 4 mounting points.. allow you to tune the rear set up more?
or is this overkill on this.

A spec built mount w/several mounting points for the front bolts would allow the end user to 'tune' the set-up per their application & be better vs a one size fits all approach.

Porterbuilt @ http://www.porterbuiltfabrication.com/ makes a T/A x-member like this. Hotchkis offers something similar too (I can't remember but I think it might be just the brackets as part of a rear kit).

[chevyrestoguy]

Originally Posted by WAAF

silly question, hope is doesn't highjack the o/p thread..
I understand the flip of factory bracket= cheap and easy
but,(always the but)
would making or useing mount like they use on a 4 link set up.. with 4 mounting points.. allow you to tune the rear set up more?
or is this overkill on this.

Actually not a silly question at all. If you made a mount like a 4 link set-up has, you have a few more options for setting the pinion angle where you want it. I considered this when I flipped my brackets. I was going to find a suitable-sized chunk of square tubing, whack off one of the sides, drill the 3 holes for adjustability, and then match-drill the mounting holes to the O.E. crossmember. I wound up just using the stock bracket because I was changing the rear end, and I was going to be setting the exact pinion angle I wanted when I welded the new perches on.

[edhtrd71]

How do you know if this modification will be usefull? My rear has 3 inch drop springs. I dont really have any traction issues seems to have alot of forward bite. (Maybe not enough horsepower) thats another issue.

[SCOTI]

Originally Posted by edhtrd71

How do you know if this modification will be usefull? My rear has 3 inch drop springs. I dont really have any traction issues seems to have alot of forward bite. (Maybe not enough horsepower) thats another issue.

Trial & error tuning.

[Captainfab]

Not a silly question....it's been done before and with good results.

http://www.67-72chevytrucks.com/vboa...d.php?t=278864

Now Hotchkis includes a set in their performance suspension package for the '63-'72 trucks.

Originally Posted by WAAF

silly question, hope is doesn't highjack the o/p thread..
I understand the flip of factory bracket= cheap and easy
but,(always the but)
would making or useing mount like they use on a 4 link set up.. with 4 mounting points.. allow you to tune the rear set up more?
or is this overkill on this.

[oldno7]

So let me ask this I'll be using a 6 inch drop spring, and ordering a new rearend since my truck has this drop moser has told me they can fix the axle saddles to fix the drop if a guy flipped these brackets do the axle saddles still need moved or not

[Hart_Rod]

Originally Posted by oldno7

So let me ask this I'll be using a 6 inch drop spring, and ordering a new rearend since my truck has this drop moser has told me they can fix the axle saddles to fix the drop if a guy flipped these brackets do the axle saddles still need moved or not

I would because it will help center the rear tires because of your drop.
Posted via Mobile Device

[oldno7]

If Moser adjust the axle saddles to fix the pinion angle, AND you flipped the trailing arm brackets that also helps with the pinion angle. Would this be overkill by doing both? I understand the centering of the wheel so flipping does make since. Just don't want two pos to make a neg

[jmlcolorado]

Can anyone tell me what the factory piñon angle is for these trucks with factory springs?
I cut mine out and modified the frame LONG before I thought of checking this.
Posted via Mobile Device