Actually, it isn't necessary to remove the engine to swap out the crossmember.
I've done 3 this way. I've made a small engine sling out of 2" angle iron. It's
just 3 pieces welded together into an upside down "U" shape, with two pieces of
all thread rod about 8 inches long that run through the top piece, and there's a
short 5 to 6 inches of chain wlded to the bottom of each rod. The chain can be
bolted to the front of the engine, and the nut on each rod can be turned down to
tighten up the chains to lift the engine up off of the mounts. The bottom ends
of the "U" rest on each frame rail, and that then takes all the weight off of
the crossmember, allowing it to be removed easily. The engine doesn't need to be
raised very far at all, just enough to take the weight off the mounts.

 As for the bolts lining up on the crossmembers, it's true that not all of them
do, but there are 7 bolts on each side originally, and 6 of those do line up,
which is enough to hold the crossmember in place without any problems. There are
3 bolts on the bottom of each frame rail, and all of those will line up, and 4
on each side of the frame rail, and 3 of those line up. That 4th bolt isn't
necessary to hold the crosmember in place, but if you don't like the thought of
one bolt not being installed, you can drill out the hole so a bolt can be ran
through it. If memory serves, because it's been several years since I've done
one of these, it's one of the bolts that have a nut welded in place on the top
rear side of the crossmember.

 There is another piece that you can bolt onto the frame to help strengthen the
spot if you like. On a lot of the newer trucks, there is a reinforcement piece
that sits inside the frame rail, sandwiching it between the bracket and the
crossmember. It's only about 7 or 8 inches long, and as tall as the frame rail,
and it's got a rolled lip on it to help keep it's shape, and all the bolts go
through them. There's one for each side. I believe that all 3/4 tons and up have
them, and I'm not sure, but I think I've seen some even on some 1/2 tons. But
this piece isn't necessary, just an option if you want to make that part of your
frame a little stronger. If you've got a 3/4 or bigger truck though, you'll want
to install these.

 But to be fair to Steve, he's right, it isn't necessary to replace the
crossmember to get disc brakes. To me though, it's just easier that way. You can
rebuild the whole front end in the comfort of your shop before you have to crawl
under the truck to replace a thing, and then you've got it right out there where
it's easy to clean and paint too.

 Another consideration when swapping the front suspension is the possibility of
changing the steering geometry. Through the years, the shape of the control
arms, and how they were mounted had changed. The crossmembers were changed
slightly as well, a lot of it depending on the capacity of the truck it was
going on. On the early trucks, there were forged parts rivited to the top of the
stamped crossmember to mount the upper control arm to. In later years, this
forging was changed to a stamped part on the light trucks, but the forged piece
was still used on the heavier trucks. Unfortunately, I cannot tell you exactly
when, or what year they did this change, but if you happen to be going to a
salvage yard, and they will let you look around, check it out. You will see what
I'm talking about.
 The reason I mentioned this, is because it can make getting the front end
aligned correctly difficult, if not impossible. When you begin to mix and match
parts from different trucks, that's entirely possible. However, if you take all
the parts from the same donor vehicle, then the alignment shouldn't be an issue.
You'll just need to remember to tell the shop doing the alignment what year the
front end came off of.

As an example of this issue, I had swapped out just the spindles and ball joints
on my '66 years ago when I did my first disc swap. I used the spindles from a
'72 truck, but kept the '66 arms. Well, the problem I had with that was when
turning either direction, the inside spindle was contacting the upper control
arm, and it's not supposed to do that. I wound up replacing the upper arms as
well to correct the problem. I could have cut off enough material on the
original arms to make it work, but I didn't care for that idea.

 Another issue you will face when swapping out spindles is the size of the outer
tie rod stud/hole. On all the drum brake trucks, 1/2 ton that is, the tie rod
stud is smaller than the disc brake tie rod. So if you do a swap, you'll need to
get the steering linkage as well, and I'd recommend you get it all, to include
the idler arm and center link. It's not possible to change just the outer tie
rod to fit the spindle on a 1/2 ton, because of the size of the rest of the tie
rod. The adjusting sleeve is bigger on a disc system. However, the pitman arm
actually has the same size stud in it, so it's not necessary to change that,
unless you're going for power steering, then you're into another set of issues.

 As you can see, it's not just a simple issue to swap out for disc brakes if you
are going to do this on your own. If you're buying a kit from some supplier,
then they usually take the guess work out of it. However, it's a lot more
expensive that way as well.

I hope I've cleared up some questions, and not raised a lot more.


 Rick Cook, SV, AZ.




________________________________
From: Steve Pekrul <fastoldcars@...>
To: 6066_Chevy_Truck@yahoogroups.com
Sent: Tuesday, June 30, 2009 6:33:23 AM
Subject: Re: [6066 Chevy Truck] something new?





There  is NO need to swap the front crossmember to do the disc brake swap-even
on the 60-62.  Even after you swap out crossmembers the holes do not align. 
There are easier ways, this guy sells instructions on ebay reasonable,. If you
have a problem, he will help.
Removing the crossmember involves removing engine.

____________ _________ _________ __
From: Devon Heron <devonh@alumni. cse.ucsc. edu>
To: 6066_Chevy_Truck@ yahoogroups. com
Sent: Monday, June 29, 2009 1:31:54 PM
Subject: Re: [6066 Chevy Truck] something new?

I've got a 65 C30, and it had the 4speed with 5.13 gears in the rear-end... ran
great with my rebuilt 292, but I was speed limited
and spinning the 292 that fast was really loud...

I put in the 700R4 and a new Dayna70 rear end (from a ford) with
3..73 gears. http://employees. org/~devo/ 65chevy/index. html for all
the details...

If I were to do it again, I would have kept the 4speed manual and
done just the rear-end swap...

The 700R4 is really nice, and it's really quiet on the freeway,
but do I really need to drive 90mph in this beast? (ok I think
I've only gone about 85 or so... but that's still faster than necessary, and the
motor isn't even spinning very fast at that
speed)

GearVendors would be a really nice way to go, but probably
more expensive than a rear-end swap. I didn't find any
info on a gear-swap in the existing rear-end, but that would
be a good option too! My route was too expensive... . lesson
learned.
-Devon

--- In 6066_Chevy_Truck@ yahoogroups. com, "Matt Bishop" <matttheelder@ ...>
wrote:
>
> Here is something new to argue about. I have a 66 c30 dually that i would like
to take on the highway. Its just a farm truck but it is the only old truck i get
right now. It has a 283 with a 4 speed. It is all original with 53,000mi on it.
I know I could swap the rear and trans but without the money or time it is not
going to happen. Are there any other options? Pinion gears? What to switch them
to? Overdrive ad on like from gearvenders? Anyone done this, are you happy with
it? Anyother options? It runs great and is in great shape. When I bought it last
year i got 14mpg all the way home before a complete tuneup. Let me know your
thoughts. Thanks. By the way, when we fight we are no better than ford people,
just kidding.
>

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