Chevelle frame brace install driveshaft issues

[claytonisbob]

Looking for a little advice from anyone that may have installed the latest version of the Chevelle frame brace kit Summit\HPI sells (or really, from anyone that want's to chime in). I got it all welded in, went together without much issue. My car has stock length bilsteins and lowering springs, adjustable length upper and lower controls arms on the rear set to stock lengths (for now, may tweak a bit when I get the weight back on the frame and check driveline angles. I went to install the driveshaft so I can work around it while I rework my exhaust to work and it runs right into the rear cross member. Would need to drop down a couple inches to clear.

Now I'm aware there is little to no weight in the back and it's sitting on the shocks end stops, once I get weight on the car I'm sure the driveshaft will clear. But it seems like now if I jack it up, there will be quite a bit of weight on the driveshaft.. or if I hit a big bump and the car rises up to full extension of the shocks (or not even full, again it'd have to be a couple inches higher to not hit.

I'm not sure if they only designed this kit for cars with rear coilovers or shorter shocks or what. Mostly wanting to see if anyone has any ideas what I could do here or if this may just be a tradeoff I'll have to lift the rear with weight on the suspension. I'm half inclined to think I may be looking at cutting this crossmember out and building something that goes up and over the driveshaft instead of under it. (please excuse my dirty driveshaft, I haven't cleaned it up yet :)

[67-LS1]

It’s hard to tell from the pictures but could the crossmember be moved slightly forward? And is that a 4” driveshaft?
I’m wondering if a slightly smaller shaft diameter and the pinion angle adjustment might get you to where you need to be. If not, a slight forward relocation of the rear crossmember should.
Another idea might be to cut out just the center section of the crossmember and replace is with a loop with the bottom located to clear when the suspension is unloaded.
Having to only lift by the wheels would be pain going forward.

[raustinss]

how did you set the height for the kit ... was it per hpi instructions

[IMPALAMAN1]

i have a modified version of their original kit. (widened and extended and notched to clear the floorpans) I am in the process of moving the rear one forward or ditch it and going over the drive shaft. car is on Air and at full lockup it is in the way and im running a 3" shaft.

[raustinss]

bingo .. the car is on air . thats the problem

[claytonisbob]

So I found my lower control arms were about 1/2" longer than the stock length (as short as they'd go with the rods I'm using). Just got some 1" shorter ones in to get be in the right range to at least get the angle where it should be stock. My plan is to use some ratchet straps to compress the springs to where they should be at ride height and check my drive shaft, trans, and diff angles and make sure they're where they should be. Possible I need to pitch the pinion up a bit more anyway. I don't know how much the pinion angle changes through the suspension movement on A bodies, but at the moment the pinion is pointed down more than I think it should be. I could move the crossmember forward, but it'd hit the floor if I pushed it forward much and it'd take a lot to get it to clear just based on that. My trans is at a good height to give me a 3-4* engine angle, before I pulled the body off I had the t56 angled down a lot more than it should have been which means I'm going to have to do more trans tunnel clearancing, but I knew that going in.

The last thing I think I could do to get an extra little bit would be to move the lower shock mount in and down a bit (like 1/2") which I believe should put the shock in more of it's sweet spot anyway since the car is lowered and would prevent the rear from drooping as much when I put it up on the lift. I think with a combination of things I'll get it to work. I'm in the process of running new brake lines, fuel lines, and modifying the headers (idk why the hooker pro comp ls swap headers are angled the way they are, they were close to my floors even before, and now they would have been DEEP into my floor if I didn't cut and modify them) atm but I'll update when I get this sorted out. Not really complaining about the frame kit, it's quite nice and gave me a good opportunity to clean up my frame and get some sins corrected I didn't do years ago.