norms 55 chevy pu build

[dsraven]

i would say run it as is. if it blows up doing burnouts or whatever it would be easy enough to replace it with another 83 camaro diff but maybe a more high perf camaro from same vintage. it's a pretty light truck out back so the wheels will likely spin pretty easily unless you do some custom traction control device.
at least it would put that cost forward a bit unless you know of a high perf camaro diff or some other donor with the same width and bolt pattern.

[washington blue]

I measured a bunch more and finally decided it was time to cut so I cut what I measured about an inch and a half ahead of the 55 wheel base. This way it will compensate for the lower stance and the rearward swing of the A arms. Also I can shorten if needed, much easier than stretching the 55 frame.

[washington blue]

I rolled the Firebird subframe under the 55 and after a lot of measuring front to back, side to side, and X measurements I eventually got them all the same. I have been measuring from the square tubing forward to the string and to the 4 A arm bolts, both straight front to rear, and also X measuring the 4 A arm bolts to the tubing. The 4 bolts are the ones that have shims for alignment on them. I don't know if there is anywhere else I should measure from.

[washington blue]

I put the fender on one side to see about wheel location and I see it is too far forward. I planned to have it a little too far forward then I could ease it back to get it just right.

[dsraven]

make sure to use the tire size you want to end up with. it can make a difference in the look of the wheel in the opening.

[dsraven]

also set up the suspension so when you check the wheel opening thing the suspension is sitting at ride height.

[Black_Sheep]

Originally Posted by dsraven

also set up the suspension so when you check the wheel opening thing the suspension is sitting at ride height.

How would one go about dialing in the ride height without the engine, trans, sheetmetal, etc... If the OP centers the wheels and welds it up like that, he may not be happy with the final ride height. My guess would be to replace the springs and shocks with some kind of fixed spacer. I miscalculated on the '58, it took 2" drop spindles and a bit of trial and error to get the front ride height where I wanted it. I could have saved time and money if I'd have given it a little more forethought...

[dsraven]

one way to get the truck to ride height is to replace the shocks with a solid link. get the suspension at ride height by adjusting things until you get the lower control arms to sit level, side to side. that is where they were engineered to be when the vehicle is driving around. you may need to remove the springs to accomplish this. threaded rod works good for adjusting height.a modified turnbuckle may also work.

[washington blue]

dsraven, thanks for your input. I have been reading other builds and you comment often and you really know a lot about these old trucks, I appreciate your input and everyone else too. As you have suggested I took the coil springs out and I have threaded rods to put through the shock holes so I can raise and lower the front arms as needed to see how everything looks at ride height. I took the thing back apart and I cut 1 1/8 inch off of the 55 frame and put it back together and it looks pretty good now I think.

[Black_Sheep]

Originally Posted by washington blue

dsraven, thanks for your input. I have been reading other builds and you comment often and you really know a lot about these old trucks, I appreciate your input and everyone else too. As you have suggested I took the coil springs out and I have threaded rods to put through the shock holes so I can raise and lower the front arms as needed to see how everything looks at ride height. I took the thing back apart and I cut 1 1/8 inch off of the 55 frame and put it back together and it looks pretty good now I think.

That looks much better centered in the wheel opening.

[dsraven]

when it is all said and done your lower control arms should be level, from inboard to the outboard (the threaded rod adjustment. thats where the steering is engineered to be when driving around) and front to rear (the angle of the subframe). that would set them correct for when you are at ride height. if you do that and then install a wheel and center the wheel how you like it in the wheel opening, for front to rear and for the look you like at ride height, then that is where the frames will need to be when it comes time to tack them together. make sure the truck frame is sitting at the rake angle you have chosen as well. a lot of guys use 2 deg down in the front but it is a personal preference thing. you can also use a plumb bob to make a mark on the fllor to check if the axle centerline is parallel to the frame. that is an important step.
good luck and keep posting pics if the progress.

[dsraven]

I guess what I am saying is try not to raise and lower the control arms with the threaded rod to adjust the ride height. instead, level the control arms because they should be level at ride height, and then raise or lower the subframe to get the wheels at ride ride height.

[one wing angel]

Hi there from another frozen Northerner.
Your post is very timely in that I am about to embark on the same journey with my 56 pickup. Pretty much the same plan and the same components. I have been scouring the posts and links for up close and accurate measurements for placement of the front clip and your pictures have been invaluable.
Thanks for posting and good luck with your project,....
I have sent a private message .......
John P

[washington blue]

Thanks, I raise the control arms with the threaded rod since the pu is hanging from jack stands, just to get the arms level so that I can see how they look in the wheel opening. I worded it poorly in a recent post.

[washington blue]

Hi one wing angel, I have several pictures of what I have done and will post them. The first thing to do is absolutely make sure your frame is square as dsraven has said. Read his advice it is very good. In this picture which I posted before it is easy to make sure the back half of the frame is square if your box is off. The right side and left side of these frames almost mirror each other and they are very accurately built. Just pick a rivet or hole that matches a rivet or hole on the opposite rail and X measure to check for straightness. I like to see the measurements 1/16 or less in variance. There can be some slight differences in rivet heads which can throw your measurements off a little so be sure to check each rivet when measuring for slight differences. I measured back to the inside frame corners which are nice and sharp and square, ( they really scratch your legs if you walk past too quickly) the tapes are just set there for show and are not precisely in place. In the second picture at the very bottom you can see the handle of a screw driver, I have that stuck into a factory reference hole which I used for a measure location a lot. There is a matching hole on the drier side just in front of the E brake mount. I X measured and front to rear measured from these holes to be sure the front half of the frame was square, then I measured back from this hole to get the one inch tubing square. I also made sure the square tubing was perfectly centered from side to side with a caliper because I planned to use the 2 ends of that square tubing for reference points to do lots of measuring. That 1 inch square tubing had to be perfectly square and centered, it is in my mind very important. Also a plumb bob and marks on the floor work well in the measuring process, I put tape on the floor and made marks on the tape since my floor is kind of rough ( it was once a hog house). In the third picture you can see my plumb bob string and if you look hard you can see green tape on the floor with an x on it. Be sure to center the string or it will throw measurements off if both sides are not plumbed exactly the same.

[dsraven]

another thing that can work well to more accurately hold the tape is to use a small plastic C clamp to hold it in place on the frame. that way you can get a more accurate measure because the tape doesn't move.
if having trouble with tape sticking to the floor you can wire brush a spot, blow the dust off and mark the floor with a shot of paint. when it dries it will hold a mark better in that it doesn't stick to your shoe if you step on it and won't come off the floor if it gets wet etc.
one thing that is pretty important is to get the frame sitting nice and solid on some stands. solid enough so it won't move when the weight of the frame is removed when cutting off the front and also won't move when sliding the new clip back on and lining things up. I welded on some cross braces in an X pattern when my frame was apart. then ground it off after everything was done and cross members were in place. I used jack stands with the sliding part removed and a piece of square tube welded on top. the tube had holes for some large threaded rod to go through vertically and also had nuts welded on the square tube to accept threaded rod. the threaded rod could be locked down to the tube with jam nuts. the rod went vertically and supported the frame. then, where the rods connected to the frame above the stands , I welded some 3/8 bolts to the end of the larger vertical rod so the 3/8 bolts could go through some existing holes in the frame. I placed one of these units at each corner and was able to adjust the frame for level and rake angle. they really make the adjustment accurate and also hold the frame sturdy and solid. of course periodic checking is advised especially after a large unit is removed or added or the frame gets bumped hard enough to make it questionable. always do your measurements for level at the same place so you know you are comparing apples to apples. I recommend a digital level, even a small one placed on top of a long level. you would be surprised at how far off the eyeball bubble levels can be even if they look dead on. then you place a digital level on and see how far out it is or can be. also, always use the level in the same direction in case the level is out a bit. a good test is to place it on something level, then turn it 180 deg and see if it is still reading level

[washington blue]

Thanks dsraven lots of good info for sure. I learned about levels being not so accurate when I built my house. I had a nice straight 8 foot 2x6 I taped my 48 inch level to quite a bit. If I was to do it again I would definitely get a laser level and a digital level.

[dsraven]

here is a pic of what i meant about the frame stands

[washington blue]

there are 2 holes in the frame the assembly book calls reference holes and you can see them in these pictures. When I was sure the frame was square I used these holes for lots of measuring points. The line scribe in the frame just behind the holes is the center-line of the 55 axle. I don't think this is really important because the firebird subframe is mounted with eye balling the tire in the fender opening so it "looks right". these holes were important for me so I got the square tubing measurements just right. It was difficult to measure from the back end with the cab in place so I was glad these 2 holes were there.

[washington blue]

After I had the sub frame on the pu and found it to be too far forward I cut 1 1/8 inch off the 55 frame and moved the sub frame back and put it in place and clamped it. I was happy with how it looked and all my measurements were good. I decided that it was ok to go ahead and weld it but first I had to clean everything really good. Roped wire brush and grinding very thoroughly, and finally lacquer thinner to get any oils off and I was ready to put it back together and clamp it in place once again.

[washington blue]

One thing I have to add is, the firebird subframe was not square where the 2 rails go under the 55 frame. I measured it many times and X measured it from the A arm bolts and other places that were symmetrical and I discovered those 2 arms were way off so they do not line up perfectly with the 55 frame. If I was to put this thing up on a hoist this would be visible from below and would just look wrong.
The important places like the shock holes and the A arm bolts and lower arm bolts are square and that is what is important,

[washington blue]

All of the little pieces of tape in the picture are places I measured from. It is interesting that my plumb bob measurements worked out to even inch measurements. The straight measures were 150 inches even and the X measures were 154 inches even with no fractions.

[dsraven]

have you tried a flap disc? they fit on like a sanding or grinding disc but work waaay better for removing rust etc. different grits but a 40 or a 60 works well for starters. they remove metal as well so be careful. faster than a wire brush and leaves a fresh metal surface. really good for a small disc grinder.

[one wing angel]

Thank you all for the replies and suggestions for making this sub frame swap just a little bit easier. As far as I am concerned you can never have to much educated opinion. Much appreciated ,
John P

[Scott2]

I just found this build. Cool project, nice back story and a solid, methodical approach. I really like getting the daughter involved. I drag my 15 year old son out in the garage when I can. He's really not too interested so I get him to help with small stuff here and there and keep hoping it will catch his interest.

Following along now to see how this goes.

A few more pics of the A would be fun!