How low before needing a C notch on rear frame rails on 67-72 C10

[HeavyHauler]

I am looking to lower the rear of my 1968 Chevy C10 4 inches or maybe 5 inches. Will I need to install C notches so that no contact occurs between frame and rear end axle tubes?

I am not wanting to cut the frame. What other modifications are needed when lowering a truck at least 4 inches or maybe 5?

[3767]

Mine is at 5 without a notch. But......ride isnt the best without it at this height. U can use drop springs and blocks to get what u want. I just did springs and if I had 2 do it all over I would use the 2 inch blocks then drop spring 2 get me where I wanted. Once u get past 4 inches u really need to have a notch. If u look at the kits that are out there now, when they get down to 5+ inches lowered they all include plates 4 a c notch. There is a reason and it's the travel u wont have without it. Even with air ride, most all of them have a c notch and not all lay frame with it.

[71cheyennesuperlongb]

I put airbags on .the back of my 71 lwb where the coils were.When I set the frame on the rearend I have about 1 inch of room before the center section hits the metal bedfloor.Wood bedfloors I think have less room than that,Ihave no c notch.When at ride height I have 3 1/2 inches between bottom of frame and top of rear end.The best thing I added were NO LIMIT shock relocaters and panhard bar.BIG difference in ride quality.

[Mike C]

I have a flip kit on my leaf spring short stepside. That dropped it 7" from the center of the wheel to the bottom of the wheel arch. I removed the factory bump stop and used the urethane puck that came with the DJM kit. It contacts sometimes, but not bad. I can't imagine having any problems with a 5" drop.

Relocating the shocks should be mandatory though. On mine I drilled the more vertical hole in the factory leaf spring shosck mount and used stock length front shocks all the way around.