Crossmember notch or Crossember drop?

[milehightoyz]

Sorry if this has been asked before but I could not find a thread on it. Ive seen a few threads on 1.5" xmember drops and Ive notice some people such as captkaos will section and drop the entire top of the crossmember down an 1.5":



And some such as fastbagged68, and phantom dually, have only notched the area where the framerails will sit recessed.



is there any preference as to which is a better way to go? what are the differences? the only difference I can see offhand is motor placement but that can be addressed fairly simply with diff motor mounts. I know that fastbagged and phantom both are going with custom built LCA's is this coincidental or necessary when doing it that way? Any info would be greatly appreciated.

[XXL]

Originally Posted by milehightoyz

Sorry if this has been asked before but I could not find a thread on it. Ive seen a few threads on 1.5" xmember drops and Ive notice some people such as captkaos will section and drop the entire top of the crossmember down an 1.5":



And some such as fastbagged68, and phantom dually, have only notched the area where the framerails will sit recessed.



is there any preference as to which is a better way to go? what are the differences? the only difference I can see offhand is motor placement but that can be addressed fairly simply with diff motor mounts. I know that fastbagged and phantom both are going with custom built LCA's is this coincidental or necessary when doing it that way? Any info would be greatly appreciated.

The first method is a bolt-in swap (except for steering linkage issues in some cases). The second requires modifying the motor mounts and sometimes the oil pan. The work required to do the first method is not significantly more than the second, so I see no advantage to doing it as in the second. (BTW, I'm biased. captkaos did my xmember.)

[milehightoyz]

Hi XXL, thanks for the reply. i understand that in the second method the motor would move up 1.5" with the xmember which may cause firewall clearance issues with the distributer. but it seems that with the first method you would have the problem of the oil pan hanging down 1.5" lower then the xmember after it was sectioned out?? the second method seems like alot less cutting and welding. also why would the second method not be a bolt in swap as well? thanks in advanced for the info.

[DM310]

Well are you only doing the x member mod or are you going to Z the frame too? I would say the first one is the easiest

[a squarecan]

I am glad some one brought this back up cause I was going to ask cause I know it has been talked about before but I could not find it either. Crossmember number 2 looks easier but you will need to modify the engine and tranny mounts. Which doesn't have to be a big deal, but it is an extra step. But I will be intrested to see how this thread turns out.

Keith

[fastbagged68]

If you do it like #1 you can not do custom lower control arms like mine. #1 is easier then what I did. Your motor mounts will work out fine. Only issue is steering column hitting upper control arm. My crossmember is a little over kill for someone that doesn't want to lay body. With my suburban aired out my control arm and my crossmember are off the ground about an inch or maybe a little less.

[a squarecan]

So I am curious if you plan on using the stock A-arms which is an easier/better fix? I know that both may not fit into same catergory, but I am just trying to figure out the best route to go. I had planned to go the route of number 1, but then number also looked like a good idea.

Keith

[Captkaos]

I am biased, but my setup eliminates all the problems associated with the notch'd version except for the steering which is going to happen however you do it.

The custom lower control arms fastbagged68'd use was setup by the same company that did his crossmember. They aren't applicable for any other setup.

ANY aftermarket control arms either dropped or not will work with my setup. XXL is running Air Rides Strong arms on his. I had stock ones on mine.

[fastbagged68]

Originally Posted by Captkaos

The custom lower control arms fastbagged68'd use was setup by the same company that did his crossmember. They aren't applicable for any other setup.

The custom control arms are Bill Turner with modifactions done to them. I did the crossmember. It has a 2 inch drop. I can make those arms too!

[Captkaos]

My bad, I thought I read/remembered that Bill made them for you and you sent the crossmember to him also.

[a squarecan]

Hey Fastbagged,

do you have any pix of your LCA's?

Also how did you manage to get 2 inches out of your cross member drop? I have heard if you go over 1.5 inches you run into more serious issues then just steering.

Thanks
Keith

[Captkaos]

He went 2" and used a rack & pinion setup, which will solve those issues.

[a squarecan]

OOOOH,

That answers that question, sounds like your way is best Chris unless I would be going with rack and pinion.

Thanks I am going to start measuring things out and take it out to the plasma this weekend hopefully lol.

Keith

[milehightoyz]

i dont know why but i decided on 3.5" z, i was originally gonna do a 3" and save the 1-1.5" xmember drop in case i still wasnt happy with the height. then as i was setting it up i said "ahh what the hell, another .5" aint gonna hurt." seems like a 3.5" z maybe somewhat of a happy medium as ive seen alot of info that confirms that 3.5" total will do the trick (2"z and 1.5"xmemberdrop) at any rate. i will keep anyone posted on updates as it comes together. also, im doing a 78 2wd blazer frame i dont know if there are any differences then truck frames. there seemed to be a slight curve inwards to the frame rails where i cut and z'd on the area i had to fish plate that noone else mentioned. maybe i cut too far forward? i didnt have the body on the frame yet so eyeballed it kinda going buy the pics on loweredd.com's website.

[Jaredm82]

I did mine 2.5" and raised my steering the same. Works perfectly

[SCOTI]

Originally Posted by Jaredm82

I did mine 2.5" and raised my steering the same. Works perfectly

Could you elaborate?

[milehightoyz]

any info or pics on what you did to raise your steering? thank john

[Jaredm82]

well, you drill new holes 2.5" higher than the origninal ones, then notch the frame were the idler arm and steering arm need clearance to move.

[a squarecan]

Hey Jared any problems you ran into with it? Has it been road tested? And Also is 2.5 inches enough to tuck the LCA's up enough to lay frame?

Thanks
Keith

[Jaredm82]

no problems what so ever. Ya I drove it for over a year after I got it done. I just recently tore it apart and lowered the body mounts down.

[Jaredm82]

http://www.fullsizechevy.com/forums/...d.php?t=165800 thats the best i can do for pics right now

[a squarecan]

Thanks for the info and pix Jared!

I just wanted to make sure it held up well because I plan on making my truck a daily driver. Good to hear you haven't had any problems! My 3" drop spindles are suppose to be arriving some time this evening so I will mock everything up with the drop spindles and find out exactly how much of that cross member I need to cut away.

It looks like you just made the frame rail taller where the box is, do you think if I "z" the frame where the box is would it be strong enough?

Thanks
Keith

[Jaredm82]

Actually, thats basically what I did. It's hard to explain, but I sliced the side of the frame and kept the bottom part, rasied the side section up, welded it back together and then welded the 2 inch peice on top to make it look like a factory bend. Make sense? Ill try and get some pics of the inside of the frame and it will explain everything! Also, yes, my a arms do sit up above the frame line by about 1/4 to 1/2" or so? I cant remember, but now my body is lower than my frame line so I can tell you for sure. I feel like I never make sense on these forums... Sorry

[Jaredm82]

Also, I have 3" djm spindles as well, and my tire size is 245/35/20. It barely lays on a 265/30/22 too...

[a squarecan]

Thanks again Jared,

Makes sense! My DJM spindles just came through the door. Now I have to wait for the rest of the brake stuff to get here. I plan to run a 245/35/20 when I can afford it but for now I will probably just roll on 15's

PIx would be awesome if you get a chance.

Keith