Spacing trans crossmember from frame?

[c-tenkid]

Hey guys I am working on my 69 c-10.It was 2wd I am converting it 4wd.I am working on installing a th350 and a 203 in the truck.I am using I believe a trans crossmember from a 74 chevy truck.

The problem I am having is that the transfer case hits the bottom of the cab and the crossmember is still an inch from the frame.

So today I made a couple 2inch spacers outta of some sqaure tubing I had.Now I have the clearance I need.But it seems like the motor is rocked back a little bit.I have not put a level on the carb pad on intake.
What I am wanting to know if anyone else has done anything like this.It's not the transmission that hits.Its the transfer case so changing the hump in the cab would do nothing.I have a freind that said he installed similar spacers on his jeep when he lifted it and it was fine.


If I found a 67-72 four wheel drive crossmember would it work better?


Thanks for any advice

[obijuan]

as long as the spacer will not create stress risers and cracks, or basically spreads the load properly id say youre ok.

there are two different crossmembers from 73+ that you could use.
a picture tells all pretty much.


seen here is a 1/2 ton and 3/4 ton crossmember

a one ton 4x4 crossmember has a shallow drop because of the taller frame. practically flat. using this would cause the issue youre describing.

[c-tenkid]

Thanks for the reply!

The tubing I used was 3x3 sqaure bout .125 wall.I cut it down and made it 2x3 and welded it back togother.So it is the same width as the frame.Also made it as long as the crossmember.So after I get the 1/2inch grade 8 bolts holding it all togother I don't believe I will have any strength issues.

The crossmember I am using has a drop in it like the one pictured on top.I am not sure what the issue is.Today I am gonna work on it more since I got snowed out from work.

Last weekend I bought a nice set of TSL's for the truck.She is looking alot meaner for sure!

[obijuan]

probably then because the 203 was never in a 69 and a 203 is stupid long compared to the 205.

[c-tenkid]

Heres a pic of the truck.And your right that 203 is incredibly long

[c-tenkid]

I spent today working on the spacers and got them installed.I also got to checking around and the frame is 34 inchs wide.And the output shaft is right at 17 inches.So it is good and centered in the chassis.

Here is a pic of the spacer I made.


Anymore input would be great

[obijuan]

id put a 205 in it. that is gonna compound your front driveshaft angle problems.

[c-tenkid]

obijaun

What about the 203 makes driveshaft alignment different than the 205?I am not very knowledgeable about the differences.I am more into drag racing and dirt track racing than 4wd trucks.

My dream has always been to make my 69 4wd.It's my favorite truck all lifted up.It doesn't get any better.

[obijuan]

the spacers dropping the tcase down make the rear angles less, but at the same time, make the front driveshaft angles worse.

[kwmech]

Being a 2wd originally, did you have a short hump floor pan or a high

[BlackhillsHD]

I have a 73-87 crossmember in mine. It was a 2wd cab to start. I put in the high hump trans tunnel, and put a 1" spacer under the transfer case cross memeber. The T case now sits at the same height as my moms CST Blazer.

[c-tenkid]

The truck has a low hump cab.I currently have the shifter installed and it sits correct in the cab.The bottom of the transmission pan is about even with the frame.


I am about done working on the truck this weekend.I have a 70 nova I drag race.And it's about time to get to the track.

I ordered a new gas tank for the truck.With a new sending unit and some other parts.They should be here shortly.

Thanks for the advice guys.When I start working on the truck again.I am going to look for a 205 to put into it.

[c-tenkid]

Well I scored a 205 transfer case to replace the 203 in the truck.So I don't have to use the spacers I made.

As OBIJAUN pointed out it would make my front driveshaft angle bad.Also I didn't like the idea of being in 4wd all the time.Even with lockouts on the front axle.

I am new to building 4wds.So I appreciate the advice.

The 205 I got has the adapter for the th350.But it is cracked.So I have to get a different one of those.

The transfer case has a bolt on style yoke for the driveshaft.They guy gave me another mainshaft and all the parts to convert the transfer case to a slip yoke style.

Would it be worth the effort to change it?Or should I just find the correct driveshaft with the slip joint in it?

Thanks again for the advice!

[obijuan]

I'd definitely leave it fixed yoke on the rear. The slip yoke is mildly problematic down the line compared to the bolt on yoke. I have an extra adapter if you haven't found one yet.
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[LONGHAIR]

Agreed, leave the fixed yoke and get a slip jointed driveshaft.
There are kits out there to convert the slip yoke style transfer cases to fixed yoke, but I have never heard of going the other way?

Also, your original question about the spacers under the crossmember raises a caution. When spacing the crossmember down, you also tip the distributor closer to the firewall. You have to be aware of the spacing there. The cab is rubber-mounted and can move quite a bit when off-road. Cap to firewall contact is bad,could leave you stranded.

[c-tenkid]

I didn't wanna take the transfer case apart anyway.So leaving it the way it is.Is fine with me.

OBIJAUN.I will take you up on that adapter.It will be a few weeks though.I just bought a solid roller small block chevy motor from a freind.It was one of those to good to pass up deals.But it stretched my project money way to thin.

Thanks again for the advice guys.

[Dale99]

Little late to the party here. But my jimmy has a v8,th350,np203. Due to spacing the crossmember down, my EFI distributor rubs on the firewall and keeps changing my timing no matter how much I tighten the hold down clamp.

So fair warning for anyone who plans to do this.

[CUSTOM/10]

Some additional info;

You may need to get a crossmember from a 70,71 or 72 NP205, they had about 12" of drop built into them.

You also mentioned you have a low hump cab, so you may also need to get the removable / bolt on high hump to put in your cab.

If you do find you need NP205 crossmember I have a one I would sell you !

Gary

[obijuan]

pics of this crossmember please.

[CUSTOM/10]

This is a borrowed pic, don't have a pic of my at this time, but can get one.

Gary

[c-tenkid]

Well I haven't been messing with my truck.I got my 70 nova street legal and have been messing around with that.

But I've gotten tired of the truck sitting taking up my garage.So I went ahead and bought a th350 to np205 adapter from advanced adapters.And I thought this was going to be a fairly easy swap.

Until I unbolted the stock broken adapter from the 205 and noticed that there was a broken bolt stuck in the case.Its the very bottom bolt in the figure 8 adapter.I've spent 30 dollars in bits and about 4 hours trying to drill this bolt out.And I've barely even gotten anywhere.

So now I am off to get a "special" bit from a friend got from a machine shop.If that doesn't work I am going to order a broken bolt extractor set from cornwell tools tomorrow.

Wish me luck.Man I wish I had never started this project now.

[c-tenkid]

Well I ended up just saying screw it and left the broken bolt in the transfer case.Not the best choice I know.But I drilled on that thing for 4 hours.And was using a left handed drill bit set I borrowed from a mechanic.The hole started going crooked and I said I'm done

So I go ahead and bolt the new transfer case adapter on.And the transfer case is still hitting the floor before the crossmember touches the frame.It is very very close.And I bet with 1/2 inch spacers it wouldn't rub.But Id really like to use no spacers at all.

Now I believe its the low hump cab causing this clearance issue.I can just cut the cab.But I'd like to have a GM cab hump like the 4wds came with.

Does anyone know where I can buy one?I can make something if I have to.But I'd really like to keep it somewhat original looking inside.

Thanks for any help

[CUSTOM/10]

There's one for sale in this thread.
http://67-72chevytrucks.com/vboard/s...d.php?t=571477

I have one in my old plow truck but don't know what kind of shape it's in !

Gary