which trucks have the double hump crossmember?

[ocbaud]

simple question

any idea on which trucks have the double hump tranny cross member? i'm thinking or redoing my exhaust with one to make it flow a little better

[shadetree]

I had a 72 with TH350, that used the double hoop trans crossmember.

[ocbaud]

Originally Posted by shadetree

I had a 72 with TH350, that used the double hoop trans crossmember.

i'll rephrase

what year 73-87 trucks, came with the double crossmember?
unless older years fit(i dont think they do)

[Ivan D.]

You don't need no double hump, what you need are these:



and a pair of these:



and you're good. Oh, and some heat insulating stuff for the speedo cable, or yer ruck will smell like burnt rubber for quite some time (guess how I know). Pics of the setup tomorrow, too tired now after installing it for over four hours...

[Yankeelights]

Where did you get "these & those?" I have the non-double-hump cross member and I just don't feel like scrounging around for another crossmember at this point in time, but I am considering dual exhaust with headers.

I wouldn't mind seeing the photos of the install so I can see how you used the offsets.

~ Dave

[QUOTE=Ivan D.;2163907]You don't need no double hump, what you need are these:



and a pair of these:

[gchemist]

3/4 tons and 1 tons have the dual hump crossmember. Look for trucks with a BB or 350 SB with a 400th tranny.


I have a custom made cross member. However, i'm not sure how well it will hold up to the new engine.

[bigblock73]

Originally Posted by gchemist

I have a custom made cross member. However, i'm not sure how well it will hold up to the new engine.

Your crossmember will be fine no matter what engine you have installed.

[Grande Rojo]

I got one out of a 78' suburban 454/th400

[Slonaker]

Originally Posted by gchemist

3/4 tons and 1 tons have the dual hump crossmember. Look for trucks with a BB or 350 SB with a 400th tranny.

When I was looking for one a couple of months ago, it looked like 3/4 and 1 tons had a taller frame. If you used all of the parts of a double hump crossmember, I don't think the brackets that mont to the upper part of the frame would reach. I don't know this for sure. It was just my observation.

I got my double hump crossmember off a late 70s BIG 10 or Heavy Half. I don't remember which one it was.

Slonaker

[bigblock73]

Eric, the early to mid 70's trucks had them, regardless of engine/suspension setups. I want to say 73-76. My '73 1/2 ton 350 equipped truck has one.

[crossy]

Originally Posted by bigblock73

Eric, the early to mid 70's trucks had them, regardless of engine/suspension setups. I want to say 73-76. My '73 1/2 ton 350 equipped truck has one.

yep, they got rid of em when cats came along, thats why only heavy series trucks,over 8600lbs. had them after that, 9no emissions required).
Slonaker mentioned the taller frames. I never really saw a need for the upper piece (brace)and that is the only thing different on 3/4 or 1 tons because they are longer for the taller frame.
A Good source is dead diesel trucks and there are plenty of those around.
If the bolts are original they shoould be 7/16 diameter with a 5/8 head but i've unbolted a lot that had only the 3/8 bots with 9/16 head.

[ocbaud]

ya'll know what size bolts hold it on??? incase i want to go to the junk yard?

[Pyrotechnic]

I probably should have done that with mine but I didn't feel like hunting down a cross member.

The ultimate would be to fab up a tubular cross member if you or someone you knew could weld.

[N2TRUX]

Originally Posted by Pyrotechnic

....
The ultimate would be to fab up a tubular cross member if you or someone you knew could weld.

That was my solution...

[neverfinished]

Originally Posted by N2TRUX

That was my solution...

I see that you have the cross member bolted into the top of the frame as well as the bottom, is there an OE cross member that bolts in the same way? I ask because I have a set of bolts hanging in that same spot with nothing attached to them. My cross member sits inside the frame and is only bolted to the bottom of the frame.

[Slonaker]

Originally Posted by neverfinished

I see that you have the cross member bolted into the top of the frame as well as the bottom, is there an OE cross member that bolts in the same way? I ask because I have a set of bolts hanging in that same spot with nothing attached to them. My cross member sits inside the frame and is only bolted to the bottom of the frame.

Most of them have legs that come off the bottom portion and bolt onto the top rail. It sounds like someone got lazy, and only bolted in the bottom portion of your crossmember after they worked on it. I saw several double hump crossmembers like that at the junkyard.

EDIT: This is Capt Kaos's doublehump crossmember (top of photo) with the extra legs in place:

http://www.captkaoscustoms.com/images/framecross3.jpg

Slonaker

[jseifert]

Originally Posted by N2TRUX

That was my solution...

Did you buy or fab that???

That is exactly what I need!!

[bigblock73]

Originally Posted by jseifert

Did you buy or fab that???

That is exactly what I need!!

Both, He paid to have it fabricated.

[benoit454]

Can someone post a pic of the said double hump crossmember?

if it's what I'm thinking of the 86 4x4 1/2 ton we had, had the double one on it, with a 700r4 and 208 t-case.

[SanitysBane]

My '74 C20 has one.

[ocbaud]

alright, i need some plans on that so i can get it built myself. come on i know you got some measurements on what i need to do!

[gchemist]

Here is my solution.


The crossmember was made by someone on this board. I can't remember who though. Speak up if it's you!!

[BaddBusa2005]

my exhaust runs above my trans crossmember, I have had dual 3" and no have dual 2.5"

[Slonaker]

http://www.speedwaymotors.com/p/4219...temNo=91628903

Something like that should work if you want to make your own, assuming it is wide enough.

Slonaker

[MylilBowTie]

The braces are a little over kill but to each his own. I can post a picture of mine tommorow.

Ivan D. Have any part numbers for those exhaust parts?