Adjustable Anti Squat brackets for rear trailing arms... Question?

[Slik66]

I have a POL Drop crossmember with Anti Squat brackets... The Anti Squat brackets have 5 holes for mounting the trailing arms (stock to 4*).

Is there a way to get these mounted "close" to the right position by calculating suspension drop?

A local guy from a body shop said the trailing arms need to be level to just slightly down at the rear end>?!?

[Rich 5150 69]

Too many variables...ride height, tire height, weight, stickie tires for the launch, how much flex you have in the trailing arms ( reinforcement plates ), overall rake of truck, spring rate, assemble it all, use the lowest hole first and see where the pinion position is, one to two degrees down at the pinion...you still may have to shim the housing on the trailing arms to optimize the setup. Use a go pro camera on a mount under the truck aimed at the pinion to get the results on a hard launch.

[Slik66]

Originally Posted by Rich 5150 69

Too many variables...ride height, tire height, weight, stickie tires for the launch, how much flex you have in the trailing arms ( reinforcement plates ), overall rake of truck, spring rate, assemble it all, use the lowest hole first and see where the pinion position is, one to two degrees down at the pinion...you still may have to shim the housing on the trailing arms to optimize the setup. Use a go pro camera on a mount under the truck aimed at the pinion to get the results on a hard launch.

Not setting it up for racing, just street cruiser.
No matter what hole I mount the trailing arms, the pinion does not point down at all.

[Rich 5150 69]

The lower you go the higher the pinion will ride up, you`ll need to start shiming it under the axle/trailing arms. this angle will be one to two degrees down from the transmission plane...long or short bed...? Two piece drive shaft..?

[Slik66]

Short bed.
Right now I have 6" lower springs in rear.
I don't have a driveshaft yet but plan on a one piece Aluminum.

I will definitely need an angle shim under the axle it seems

[Slik66]

Hard to see, but if I draw a straight line from the axle to the tranny, it will be just above the tail shaft of trans.

[PGSigns]

I always bolt the tranny to the crossmember first then drill the frame holes. That way they end up in the correct place. I would remove the bolts at the frame and pull it up tight to the trans and see what needs to be done to the cross member at the frame end. I am also one who likes to set the engine angle with the cab on.
Jimmy

[Slik66]

Crossmember was a tight squeeze in the frame rails so there's no give on either side.
I think I'm going to cut the mount area off the crossmember and move it up, since I need to get the tranny up off the crossmember anyway. Got a buddy that owns a powder coat shop so I can get it re powder coated after I do that for nothing.

[Slik66]

So, since this is my first full build frame off thing.... my thought was to center the transmission in between the frame rails. Is this not correct?

I can modify the trans tunnel if needed, but wanted to keep a straight line to the axle?!?!

[PGSigns]

Doing it with the cab on will let you see a couple of things on is the angle because if it is low in the back the HEI will hit. I just took a second look at your cross member in the pictures and it looks like it is upside down. All the ones I have used or built that mount faced the other way. This may solve a lot of issues bot now and in the future. I would pull it and flip it over and see how it looks. I think you will find it fits fine.
Jimmy

[Slik66]

This is the way it's made to go from the MFR... I took another pic. There's no way I can flip it around because the crossmember will be hitting the pan, if I'm understanding you correctly.

It's made to let my exhaust tuck up above the crossmember...

[Slik66]

I just called Western Chassis... Crossmember is in correctly.

They couldn't tell me why the transmission is hitting though.
Easy fix