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-   -   c-notch or not (https://67-72chevytrucks.com/vboard/showthread.php?t=132503)

davidt 12-21-2004 03:57 PM

c-notch or not
 
I've finished installing the 4-link on my truck. I was wondering if there was a basic rule of thumb for determining if the frame needs to be notched or not. I understand all the variables to consider like spring rate and ride quality. My truck obviously won't be carrying any cargo in the bed. I would like to avoid cutting the frame if I can but also I don't won't to get the truck together and realize I need to take it back apart to redo it.

Prerunner1982 12-21-2004 04:48 PM

you running bags? or what? it really depends on how low.. you want to go..

r0lf- 12-21-2004 05:59 PM

Yeah, your gonna have to give us more info on this. Almost all of us still run leafs, soooo... with your 4 link and shock setup we have no idea how much clearance you have. I have about 7-8" drop in the rear and I 100% need that notch. If its the typical 5-6" of drop in the rear, you can get away with not putting it in if you dont haul anything.

Give us some more info.

SanitysBane 12-21-2004 06:04 PM

i belive you need atleast 3 inches between the top of the axle tube and the frame.

loblazer 12-22-2004 02:32 PM

I put a 5" flip kit in my Blazer and had to C notch. I had 2" from bump stop to axle. It might have been the old springs sagging some but a small notch is no big deal and easy. I put in a 5" C. I now have new springs to install so may get more clearance back?

Captkaos 12-22-2004 02:53 PM

If it has been lowered any more that 4", it will need a C-notch regardless of how it got dropped to get full travel.

davidt 12-27-2004 12:38 PM

I don't have bags, just a straight coil-over kit. I beleive the spring rate is #450lbs per side. I'm not sure the total amount that it has been lowered. If someone could give me a frame to axle measurement on a factory height truck with good springs that would help. Mine has about 2 inches between the top of the tube and the factory stop. I removed the stop and the bracket to put on a lower profile stop like in the summit catalog. I think i could squeeze out about 3.5 inches then. The coilovers are pretty stiff and fully adjustable. I'm planning on running about a 30 inch tall tire so that means I will have to keep the back down low to keep the truck sitting right.

davidt 12-27-2004 12:44 PM

By the way if someone could send some pics of thier truck with a similar set up it would help. It is a 77 step side. I'm planning on a 30 inch street slick or drag radial to fill up the rear fender. The truck is lowered but not going to be in the weeds. Just looking for a good pro street stance. If anyone is running a similar set up I'd love to see the pics.

SCOTI 12-27-2004 06:56 PM

Try driving it the way it is first & see if it needs a c-notch.

My 74 has the HD leaf option & I have a flip kit + drop shackles for @ least 7" of drop & haven't installed my c-sections yet. Do I need them? @ this amount of drop, yes. Is it driveable @ this amount of drop & w/o the c-notch, yes . .... but it easily bottoms out on sudden dips & bumps.

The point is, everyone told me "you must have c-sections when you do a flip kit" & it wasn't mandatory. Once I added the shackles it is mandatory if you want to put any weight (like a spare tire) in the bed. IIRC, the measurement between the top of the housing end & the lower part of the frame rail is about 1 - 1.5" max.

Grande Rojo 12-27-2004 07:27 PM

1 Attachment(s)
Quote:

Originally Posted by davidt
I don't have bags, just a straight coil-over kit. I beleive the spring rate is #450lbs per side. I'm not sure the total amount that it has been lowered. If someone could give me a frame to axle measurement on a factory height truck with good springs that would help. Mine has about 2 inches between the top of the tube and the factory stop. I removed the stop and the bracket to put on a lower profile stop like in the summit catalog. I think i could squeeze out about 3.5 inches then. The coilovers are pretty stiff and fully adjustable. I'm planning on running about a 30 inch tall tire so that means I will have to keep the back down low to keep the truck sitting right.

Here's my 77' (sorry about the crappy picture) the rear has 31" tall tires
Rear has a flip kit and 2" shackles.. the front has spindles and 2" springs.
Hope this helps ;)

Grande Rojo 12-27-2004 07:30 PM

1 Attachment(s)
heres another pic with rally wheels 285/70/15

davidt 12-28-2004 11:25 AM

Grande Rojo:
that pic helps alot, what is the rim size and tire size in the first pic? Also, not to have you crawl around under your truck, but what did your measurement end up after the flip and shackle kit from the top of the axle to the bottonm of the frame. Did you c-notch or not?

davidt 12-28-2004 11:26 AM

By the way... sharp truck!

bloertcher 12-28-2004 11:18 PM

if in doubt,notch it.I notched mine cheap and simple,and you've probably got the stuff laying around your garage.I took a piece of 6" pipe,split it down the middle,cut out the frame and welded in my "half pipes".I then took some 1/4" plate and boxed a 12" section of the frame where the notch is,Clean,simple,and as strong or stronger than stock.

davidt 12-29-2004 12:40 PM

That sounds cool. I think I have seen some pics on here like that. May have been your truck.

Grande Rojo 12-29-2004 07:57 PM

I had to c-notch mine also the axle was a few inches from the frame. I also had to notch the floor of the bed. The center section of the rearend hits the bed floor under suspension travel.

davidt 12-30-2004 11:54 AM

Quote:

Originally Posted by Grande Rojo
I had to c-notch mine also the axle was a few inches from the frame. I also had to notch the floor of the bed. The center section of the rearend hits the bed floor under suspension travel.

I don't think my center section will be that close. Do you know what the axle to frame distance was before the notch. Also what size are the rims/tires in the first picture?( the torque thrust not the rally's)
:confused:

Grande Rojo 12-30-2004 04:57 PM

Quote:

Originally Posted by davidt
I don't think my center section will be that close. Do you know what the axle to frame distance was before the notch. Also what size are the rims/tires in the first picture?( the torque thrust not the rally's)
:confused:

rear -17x9.5" wheel 275/60/17 tire
front - 17x8" wheel 235/55/17 tire


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