Yet another GMC build

[1955GMC]

I saw Kabwe's cowl photo on January 11, 2011 but there is only the one (or did I miss another few?). It is hard to see how he did his in that photo angle. I agree about someone making these in the aftermarket. I looked thru on the online companies and I did not locate a vendor. This is a job I'm going to jump on AFTER I get the old girl up and running. I'm looking at this as a project that will never be 100% complete and the small stuff I'll jump on when I feel like it. Like you, I'm not a fan of body work and paint and if I work on it when I feel like it it will turn out better.
Thanks for the help.

[OKGMC4]

I think he had more pics on the old thread before he had to repost everything. Kim57 did the same thing here...

http://67-72chevytrucks.com/vboard/s...283107&page=11

...and there's lots of good pics.

[yossarian19]

I might not be seeing this correctly, but it looks like your coil over mounts are separate from the K member and are welded to the frame.
If so, I'd recommend strengthening both the coilover and uca mounts by connecting the two with a removable plate. Maybe a rectangle 3"x4" with ears that bend down & get secured by each upper control arm bolt & on both sides of the coilover bolt.
I think if you can tie that UCA mount in to something else & give it some structure you can keep the sheet metal K member with just your coilovers.

[hp1957]

OKGMC4, Mounts we made for both the 56 and 49 do NOT attach to the stock vette K-frame they go all the way through the 56 frame rails and on the caddy they attach to a heavy piece of box tubing that was added where the old cross member went. These were still both braced back to the vette k-member where the a-arms bolt. ITS BETTER TO OVER-BUILD being an ex-frame man I have seen lots of frames spread and flex and knew this would happen if we did not build having that considered in advance. ALLWAYS GO OVERKILL

From my bro Albert

Harvey

1957 Chevy Stepside
1958 GMC Fleetside C4 build thread: http://67-72chevytrucks.com/vboard/s...65#post5510465

[hp1957]

OKGMC4, If you look close you will notice the heavy gussets added to each side of the shock mounts. those were added to both the 56 and 49. the 49 has a "bolt on" brace from the mount back to the k-member because Mario wanted the k-member to be replaceable. The 56 using a much longer shock, we even added a solid piece of "bar stock" and welded it inside the upright shock mount for extra strength. The way we tied Marios k-members to the RE-ENFORCED frames help strengthen the k-member. I think it needs to all be built where the frame rails help the k-member and the k-member helps the frame before you even start to build shock mounts

From my bros Albert & Mario

Harvey
1957 Chevy Stepside
1958 GMC Fleetside C4 build thread: http://67-72chevytrucks.com/vboard/s...65#post5510465

[hp1957]

OKGMC4, check your pm.

Harvey
1957 Chevy Stepside
1958 GMC Fleetside C4

[OKGMC4]

Thanks for the pics, Harvey. Sorry about being out of it for awhile. I've been doing a honey-do task to the tune of 23 cases of ceramic tile in the kitchen, pantry, laundry room, walkway, and entryway for the wifey. Those sorts of things put the truck back of the list.

I took the advice to brace the mount back to the k member to heart. This weekend I used an angle finder with some steel and a c clamp to move the k member back into a 90 degree position. Glad it was this easy, as pulling the engine did NOT sound good. Once I got pulled into place I actually moved the k member over about 1/4 inch both sides. At this point I welded in sections of 2x2 1/8 wall square tube. They are welded to the k member, the frame, and the mounts. Should help keep it better. I also re installed my mega weak vette mono spring with no shims, and dialed my coil overs to the lowest recommended setting, 1/2" compression. This served two purposes...1. the frame never seemed to have a problem until the coil overs, maybe the vette spring kept tension in the right places to stop the twist?, 2.The vette spring was too weak by itself and 400 lb 12" springs were slightly too weak (you are right that 500 might have been more appropriate) but together they work well. The truck definitely sits higher now but seems to ride well and corners great. The mono spring acts to help out the tiny front sway bar as well. I don't think this thing could bottom out now if I wanted it to. If you have any suggestions or think this won't work let me know.

[Wheelie]

I feel your pain on the spring bind, I learned the hard way on a few customer cars. If you went with a stiffer rate like I would guess 550 or even more with an adjustable shock you would get rid of that spring bind. If I remember correctly the spring should only be preloaded 25% of its total unbound length If you didnt already know. HTH!

[OKGMC4]

I realized I hadn't taken any pics of the truck since the front suspension change so I tried to take some good ones yesterday. I waited until days end to get a better diffuse light and tried different angles on the top level of a parking garage. Didn't realize how hard it is to get one where there's no wash out, I deleted several where it looked white on top and orange on the bottom. I't also hard to avoid reflections of other things in the paint and shadows in odd places. Not really a photographer but a few turned out nice.

As far as the front goes it's a ton higher now but it drives great and never ever bottoms out so I guess I'll leave it alone. It could possibly benefit from going from a 1" front bar to a 1.25 bar as I think my nose heavy weight is taxing the lean in the turns. It's not really bad, mind you, but I'm trying to get sports car handling and with C4 suspension it should be attainable. Though I am frustrated. I live close to a road course, Hallet racing, and would be willing to pay the fees and take the driving class to do the course but they have a strict NO TRUCKS rule that I think is asinine. I could run my base model, underbraked, 170hp 92 firebird there but not my C4 suspended LS powered 1956 gmc !!!

[1955GMC]

I love this truck, the stance is perfect and it looks very fast while sitting still.
I'm posting because after I first started reading your build thread I have been watching Craig's List and E-Bay for wheels at the bargin prices you mentioned on the first few pages. I finally found a great set of '03 Vette 5oth aniversary thin spoke 17 and 18 inch wheels for under 400.00 for the set. Took me some time but bargins can be had.

[OKGMC4]

I did some research on intake air temps and found that not only is colder air better than hot for performance but an injected engine makes this even more so....as the intake air temp increases the ecm retards timing accordingly. That means you're losing power and probably fuel economy as well. I borrowed an idea from JML55's truck and got rid of the top mounted airbox, but did my new airbox in fiberglass rather than stainless. Inside is a cone filter fed through the core support. I verified before and after with live data from my OBDII scanner and I have dropped my IAT by 47 degrees on a 55 degree day from 109 down to 62. And that's sitting still idling. It does run smoother and quieter but I have no way of verifying any power increase.

With the top box out of the way I decided to do an intake cover. I took a new camaro cover, cut out the center and bolted it together with an aluminum strip and bonded it with epoxy. Filled the oil fill hole with an old wheel cap and painted it silver with orange flames. On the last piece of tape some of the silver lifted so rather than repaint the whole thing I brushed a black outline on all the flames to hide the screw up. Not as nice as I wanted but I can redo it later. It's sunny outside so I'll just drive it awhile...

[Kim57]

Looks good.
Kim

[mknittle]

I may be a little different but I like it better without the cover over the air filter.

[JMac11]

What did you do with the first box you built..... looking to put something similer together under a cowl hood.

[OKGMC4]

Originally Posted by JMac11

What did you do with the first box you built..... looking to put something similer together under a cowl hood.

Sittin in the shed gatherin dust. Can't stand the idea of tossing it, hours of work went into it.

[OKGMC4]

Back at the beginning of the month I took the truck to the drags and it ran consistent 14.5 and 14.4 second times. Not too awful for a stock 5.3 with 3.08 gears. Had a fun time but now the truck has left town to live with my parents while I start the next project. Just not enough space. I've started a 69 chevy that will become a GMC with an LS motor and some heavy body mods. The link is in my sig if anyone is interested.

[Dieselwrencher]

Very nice work on the air filter relocate. I'm sure it's nice to be able to drive it now. I agree about just driving it now. Might as well while the weather is good for it.

[OKGMC4]

Been driving the truck a few years now and put 15K miles on it. Need to do some freshening to get it back on track. Kind of neglected it while I’ve been focused on the unibody build. Steering wheel was never perfect but wanted to get rid of the brushed look and get a wheel wrapped tighter than I did it all those years ago. When the grant adapter stripped out it was the last straw. I bolted on the 9 bolt adapter that came with the column and ordered a new LeCarra. Have more plans, and will execute them in the near future.

[OKGMC4]

Old wheel

[iowaboynca]

thanks for the update. Glad to see its being driven!

[OKGMC4]

Not all the play was eliminated in the steering so I checked the rack. It was fine. Took the column apart and it was worn near to breaking at the tilt swivel. Did some investigation and it turns out the Chinese columns are terrible, and I had the worst one. The one made by Helix. More info here...

https://www.lvvta.org.nz/documents/i...ng_Columns.pdf

I am in the process of installing the (better) column i bought for my 69. It’s not chrome so I’m painting it to match. We’ll see how it turns out.

[Mains52]

Very Nice Sir. That orange has a special place in my heart via my first car. Nice choice.

[OKGMC4]

The column is a CPP. I know the article says they are not as good as the FR and Ididit columns but it looks like the biggest issue was the quality of the plastic swivel ball. I took this one apart and inspected it beforehand and it seems fine. I already had it, it was supposed to go in my 69 c10 but that truck isn’t finished yet. At least it has the failsafe built in like s GM tilt column. The Helix column does not, so I could have potentially lost all ability to steer.

[OKGMC4]

Originally Posted by Mains52

Very Nice Sir. That orange has a special place in my heart via my first car. Nice choice.

Thanks! I always wanted a 69 GTO in that color, and I grew up watching a certain Charger jumping creeks in Hazzard county so it seems the color was predestined to happen. Sure gets a lot of attention!

[OKGMC4]

A Summit box arrived today. It’s like getting a box full of shiny gold coins. Several parts to perform the next few upgrades.