Trailing arm length, C-Notch Placement

[52 Rat]

Guys, I just picked up a new set of NASCAR trailing arms this weekend. My concern is the U bolt size and the axle seat hole location. Keep in mind I am installing the arms in my 52 AD project using a '70 trailing crossmember. The U bolts I have are 4.25" not 3" like the stock axle seat. The guy I purchased the trailing arms from supplied the new U bolts and nuts. I need new trailing arm axle seats and from what I am seeing on line, they are all for 3" axle tubes not 4.25". What am I missing here? Any advise is greatly appreciated.

[Blue666]

[Guys, I just picked up a new set of NASCAR trailing arms this weekend. My concern is the U bolt size and the axle seat hole location. Keep in mind I am installing the arms in my 52 AD project using a '70 trailing crossmember. The U bolts I have are 4.25" not 3" like the stock axle seat. The guy I purchased the trailing arms from supplied the new U bolts and nuts. I need new trailing arm axle seats and from what I am seeing on line, they are all for 3" axle tubes not 4.25". What am I missing here? Any advise is greatly appreciated.]

The U-bolts lay diagonally across the axle housing rather than perpendicular to the axle housing. The extra 1.25 allows for the extra distance of the diagonal.

Is there a spell check in the quick reply? Way too early in the morning for a spelling test.

[52 Rat]

Originally Posted by Blue666

[Guys, I just picked up a new set of NASCAR trailing arms this weekend. My concern is the U bolt size and the axle seat hole location. Keep in mind I am installing the arms in my 52 AD project using a '70 trailing crossmember. The U bolts I have are 4.25" not 3" like the stock axle seat. The guy I purchased the trailing arms from supplied the new U bolts and nuts. I need new trailing arm axle seats and from what I am seeing on line, they are all for 3" axle tubes not 4.25". What am I missing here? Any advise is greatly appreciated.]

The U-bolts lay diagonally across the axle housing rather than perpendicular to the axle housing. The extra 1.25 allows for the extra distance of the diagonal.

Is there a spell check in the quick reply? Way too early in the morning for a spelling test.

Awesome! I ordered the weld on axle seats from CPP this morning.

[Bartonius]

Blue666, that makes sense, I had a spring shop bend me up some dropped u-Bolts for 3 inch tubes and they took some persuasion to get into the NASCAR arms.

[Captainfab]

If those new U-bolts are 4.250" center to center, that is about right. That would make them 3.50" on the inside. With the angle of the trailing arms in relation to the axle tube, that is what they should be. If they are indeed 4.250" on the inside, then that is a bit wider than they need to be. If you need a set of custom trailing arm mounts let me know.

Originally Posted by Blue666

[Guys, I just picked up a new set of NASCAR trailing arms this weekend. My concern is the U bolt size and the axle seat hole location. Keep in mind I am installing the arms in my 52 AD project using a '70 trailing crossmember. The U bolts I have are 4.25" not 3" like the stock axle seat. The guy I purchased the trailing arms from supplied the new U bolts and nuts. I need new trailing arm axle seats and from what I am seeing on line, they are all for 3" axle tubes not 4.25". What am I missing here? Any advise is greatly appreciated.]

The U-bolts lay diagonally across the axle housing rather than perpendicular to the axle housing. The extra 1.25 allows for the extra distance of the diagonal.

Is there a spell check in the quick reply? Way too early in the morning for a spelling test.