Help with difficult problem!!! ‘83 K5/4” lift/NP208 mounting height with incorrect homemade spacers vs correct spacers???

[BlazerBill]

Hello everyone! I have several unusual problems, not just mentally, but also with my ‘83 K5 that I’ve been restoring and am ready to install a new crate SBC350 and the original (rebuilt) 700R4 tranny and NP208 transfer case that I pulled out of the K5. When I got the K5, it already had a 4” suspension lift and the trans/TC crossmember had what looks like cut off shock ends as spacers mounted in b/w the crossmember and the frame. It also had body bushings as spacers mounted under the transfer case adapter. See pics. I purchased new/correct adapter spacer mounts from ORD but now with using just the correct ORD spacer mounts, the crossmember bolt holes are about a 1/2 bolt diameter off of one of the four frame bolt holes. My guess is that since a previous owner installed the 4” lift, they spaced the crossmember down by using the 1-1/4” high cut off shock ends to reduce the rear driveshaft pinion angle however they also spaced up the TC adapter by installing the 2” high body bushings underneath the adapter. Effectively, this homemade configuration caused the adapter to be a total of 5/8” lower versus using the correct ORD adapter spacer mounts with no spacers in b/w the crossmember and frame. Since the crossmember to frame bolt holes don’t line up now using the correct mounts, I’m now wondering if I have the correct crossmember. Should I elongate the one hole that doesn’t line up? It is because of the shock end spacers that allowed enough “misalignment” in order to get the crossmember bolts in whereas the correct configuration of the crossmember when completely flanged up to the frame will not allow the one of the four bolts to go through. I confirmed in my Chevrolet Factory Assembly Manual that shows the crossmember bolted directly to the frame without spacers under the frame. Sorry for the lengthy explanation and problem difficulty. Hopefully, you guys can help me figure out what I should do. Thanks so much!!!

 

[bucket]

That is the correct crossmember for an '83. Is it possible that you have the crossmember flipped around backwards?

How far off are the mounting holes?

Oh and there should be spacers, however, they simply go ABOVE the frame. All they do is allow the use of longer bolts, which are less likely to break when the frame flexes since they have more room to stretch.

 

[BlazerBill]

Thanks, if I turn the crossmember around more bolt holes are off. When positioned when one hole is off, it is off about a 1/4”. The bolt is a 1/2” diameter. I also need to know how high or how low the adapter should be considering the 4” lift. Obviously, the angle of the eng/trans/adapter and transfer case need to be aligned in order for the adapter to be bolted to the transmission and output shaft is aligned to properly engage the TC splines. So, if I mount the adapter properly with the correct adapter mounts and no spacers b/w the frame and crossmember, the adapter will dictate the alignment of the engine/transmission and transfer case, then what do I do to ensure the correct pinion angle of both driveshafts?

 

[idahovette]

Don't think I've seen 1/2 inch bolt for a crossmember??? 3/8 maybe 7/16??

 

[Old Guy Bill]

I believe we touched on this in your previous post.
You may need to loosen the motor mount to frame bolts to get a little wiggle room for the crossmember to line up. I believe those crossmember bolts should be 7/16” diameter bolts not 1/2” also.
The drive shaft angle may require the reared to be shimmed at the mounting pins.
The NP 208 is going to need a double cardigan in the drive shaft after the slip yoke.

 

[BlazerBill]

Okay, the engine and trans are not yet installed. I stumbled across this issue when trial fitting the crossmember and adapter with the new mounts. I cannot get the one bolt hole to line up and don’t think that even a 7/16” bolt would fit. Maybe a 3/8” bolt but is that sufficient? Or, should I open the hole up for the 1/2” bolt? I have a double cardon joint on the front driveshaft only and it looks like the rear axle has been tilted upwards. So, What else should I do? What angles should the driveshafts be at?

 

[bucket]

With a 4 inch lift, the angles "usually" don't need addressed. That is built into the lift springs and the proper lift blocks, if equipped. If you get a driveline vibration, it's something you'll need to look into.

The factory bolts were 7/16". If 4 of those don't fit, imho, just open up the hole on just the one.

 

[BlazerBill]

The 7/16” bolts did work. Not sure why the bolt holes were grinded open for 1/2” bolts to be installed. Thanks for all your input!

 

[rockriver]

Open up the hole. Don’t worry about angles unless you get vibration.