Factory transfer case crossmembers, different heights, what did they come off of?

[broflow]

I'm figuring that someone will know this off the top of their head. Here goes. I want to use the factory style tcase crossmembers to mount my doubler set up. My rig is a 78 K5. I have no idea which crossmember it had in it to begin with. I had a t350/205 to begin with (don't know which crossmember that was). In the pictures I've got 3 different styles, each drops a different amount. I know the one on the left (least amount of drop) is out of a ton truck that I scrapped recently. As for the middle one and the one on the right I don't know. I want to run the style on the right. As you can see I already modified that one. I added some channel to it to bolt it up to tabs I added on the outside of the frame. I want to find another one like that to modify to match so I can have one on the doubler adaptor and 1 on the 203 adaptor. It measures just a little over 5" from top to bottom, the middle one measures 4" from top to bottom. Of course I have 3 of the 4" ones and 2 of the shallow ton style.
Can anyone let me know what year the 5" top to bottom one came out of? I'm guessing it might of been an older blazer? I haven't started junkyard searching yet since I'm not quite sure which year to look for. Or possibly it has more to do with the tranny/transfercase set up 203 vs 205 vs 208?

 

[yellowK20]

1-tons use the flattest x-member because the frames are taller

 

[obijuank5]

84 and older used the flat two left ones. flat one is for 1 tons and middle is for the rest. 85 and newer use the double hump or w looking ones with a couple variants on shape and humps. key is the high center.


I used one tons first style crossmembers for my doubler in my k5. brought the driveline up a little higher.

 

[sweetk30]

also 85-up style bolt under frame rail lips for 1/2 and 3/4 ton .

1tons bolt up inside the frame rails .

 

[diesel4me]

A guy I know is swapping a TH400 into his '85 K20,which had a SM465...(yeah,I kmow,its a downgrade in most members eyes here,mine included--I would have just put a new clutch in it if it was mine,but he has a GF that cant drive a stick and he's sick of shifting)..

Anyway,his dilema is the T-case in his truck bolted up to the adapter that came with the TH400 (I am pretty sure its an NP-208),but his crossmember is flat like the first two pictured,and the adapter "foot" is too short to reach the mounts..
He asked me what do I need ?--a taller adapter,a different crossmember.or both ?..
Unfortunately I had no answer for him,never having done such a swap since my '72 K5 days 30 years ago..
I suggested maybe he could just make a spacer to take up the difference in height--seems to me someone here had a thread going on this recently ...?..

 

[broflow]

84 and older used the flat two left ones. flat one is for 1 tons and middle is for the rest. 85 and newer use the double hump or w looking ones with a couple variants on shape and humps. key is the high center.


I used one tons first style crossmembers for my doubler in my k5. brought the driveline up a little higher.

Ive got my case up as high as I could get it without cutting out the floor. (Case is clocked up and have a 1.5"body lift) I still need the far right crossmember. I don't think that crossmember is out of an 85 or newer though? I cant remember what they look like but I do remember that "double hump" look though.

 

[obijuank5]

The right crossmember is unfamiliar to me but looks like first gen dodge or something .

 

[broflow]

The right crossmember is unfamiliar to me but looks like first gen dodge or something .

The right crossmember and the middle one are the same except that the right one has 1" more height to it. Don't be confused by the extra channels that I welded on it to allow it to be bolted to the tabs I added to the out side of the frame. (see pict.) I did this because I boxed the frame and am not able to run nuts inside the frame channel.

 

[nvrenuf]

I don't have it in front of me to measure but I had a crossmember from a 1st gen that looked like the middle one but had deeper bends. Maybe that's what you have.