Heavy Duty 3800 5K bags need cupped. How deep do they need to be? Car hauler C30

[jarrodblake]

I have a 1970 C30 with 1975 C30 front suspension. The truck is a car hauler. 31 tires. I'm not planning on slamming it but like to be able to lower it when I need clear the dovetail in low spots and to raise it to help with loading and I would like to be able to air it up when I have a heavy load on it to keep it for riding on the bump stops.

I ordered the bags from Chassis Tech. They are the 3800 bags rated at 5,000 LBS Each. The compressed height is 4.5 Inches, Normal Height is 9 Inches and max extended is 12.5 Inches with a diameter of 9 inches compressed.

I have already cut one of the control arms to be cupped. I don't know how deep I should cup it? From most the the threads I have read it looks like most people do a 2 or 2.5 inch cup as most bags are 2.5 compressed. However my bags are 4.5 inches compressed. So should I cup mine 3.5-4 inches?


Pics of the bags.

IMAG1652 by jarrod vanwinkle, on Flickr
IMAG1671 by jarrod vanwinkle, on Flickr

I don't have fittings yet I just have a valve stem wedged in there leaking air max is 12.5 but its not to it in the pic, but you get the idea.

IMAG1654 by jarrod vanwinkle, on Flickr

unmodified control arm.

IMAG1650 by jarrod vanwinkle, on Flickr

IMAG1651 by jarrod vanwinkle, on Flickr
IMAG1655 by jarrod vanwinkle, on Flickr

compressed this would be about a 2 inch cup

IMAG1657 by jarrod vanwinkle, on Flickr

IMAG1658 by jarrod vanwinkle, on Flickr
IMAG1659 by jarrod vanwinkle, on Flickr


Should the cup be angled like factory?

IMAG1664 by jarrod vanwinkle, on Flickr

or should it be a even all the way around?

IMAG1666 by jarrod vanwinkle, on Flickr




heavy load



stock height maybe a bit of sagg.


IMAG1663 by jarrod vanwinkle, on Flickr