Chevy K10 '78 LWB

[Antti]

All right, I finally completed the 52" front spring swap yesterday! 

Basically what it took was:
- means to get the front of the truck up and secured
- air grinder for removing rivets
- lots of time and nerves 
- drill bits and a hole saw
- some steel plate for longer shackles
- and about 2,6 kilos (over 5.7 lbs) of bolts, nuts and washers. 

I'll post pics and details of it soon... Just hope to find my camera first! Just can't figure where the heck it went... 

[Antti]

I know that this topic has been well documented on the net many times before, but here's it once again.

The idea is to use stock 52" long Blazer/1/2-ton rear springs at the front. They are approximately 4" longer than stock front springs and provide better ride, more flex, and ~4" of lift. The stock hangers can be used, if you move the front ones forward as described later. Front hangers move 4" forward, but then it's  also good to move the rear hangers a couple of inches forward to gain shackle angle more suitable for positive arc springs (so the distance between the hanger eyes will only be ~2" longer although the springs are 4" longer).

As you can imagine, this would move the axle also about 2" forward. To be able to use the stock steering I moved it back again about 30 mm / 1-3/16" by drilling new holes to the spring pads at the axle and to the U-bolt plates (seems afterward that an inch would have been enough). The new rear hanger position will be higher than stock and you also need to use much longer shackles to prevent the spring rear end to hit the frame.

Ok, here's the passenger side front spring hanger in stock position.


Here's the new position of the hanger on the driver side. The L-shaped bracket will move to the front of the radiator core support bracket. Eight rivets per side has been removed. I think this was the most painful part. I did it w/ an air grinder with a small ball-shaped grinding head, and with a 10mm drill. Grinder worked pretty well but my little compressor spinned it only a few seconds at a time and then I had to wait for it to build pressure again. Stock bumper can still be used on '73 - '80 trucks, there's even no need to unbolt it.


After drilling a couple of new holes and grinding a couple of old ones to match, the hanger could be attached. Also needed to make spacers to the frontmost bolt positions at the frame rail by welding together some square washers. I used very hi-grade 10 mm (~13/32") bolts for everything at the hangers.

[Antti]

Then the rear hangers. There's a passenger side one at the stock location. I was lucky to have bolted on rear hangers instead of riveted.


Driverside hanger removed.


The original bottom front mounting hole will be new bottom rear mounting hole. I sprayed some paint on the old hanger position, pressed a paper on it, cut a bolt hole with a sharp knife and used the paper as a shablon to mark the positions of the new large center hole and the new bottom front bolt hole with center punch.


After drilling the new bottom front bolt hole with a drill bit and the large hole with a hole saw (I used 45mm / 1-25/32" hole saw), I bolted the hanger on from outside of frame rail with the two bottom bolts. Then it was easy to drill the upper holes exactly to the right positions. Here's the hanger assembled to the new position.


But hey, I think I'll continue this story later... Good night, everyone! 

[oldwhity]

Looks like fun grinding out all those rivots. I like your jack stand. Is that the roll-a-way version? lol

[friendlytruck]

cool Finland you say

[Antti]

Morning, guys!

I like your jack stand. Is that the roll-a-way version? lol

Yeah,  Just wanted some extra support, although I think I put most of the weight on the rear jack stands (just rearwards from the rear spring hangers). Three supports kept it really steady though, when working with the front hangers. That maple wooden chopping log I got from the yard was just the right length. Must weigh a good 150 lbs at least 

But I'll continue later, got to work now!

[Antti]

Here's the front spring attached. Since stock bushings of the rear springs are narrower than the bushings of the stock front springs, I made spacers to both sides of the springs by welding together some 14 mm fender washers. (2 springs w/ 2 eyes w/ 2 spacers each -> 8 spacers to make) I couldn't find long enough 9/16" bolts from my local store, so I had to use just a wee bit smaller 14mm bolt at the spring eyes.


Here you can see the spring center pin lurking from the new hole at the spring pad.


The steering link doesn't look so bad at all, much so because of the raised steering arm. It can well take the full droop of the axle, and there's also far enough space for it to be adjusted.


I made the shackles from 30mm x 12mm plate (about 1-3/16" x 15/32"). I know it's too narrow and will propably brake the bushings over the time, but that was best material I could have last weekend...and I just had to get it rolling. They're 178mm/ 7" from bolt eye to bolt eye. I managed to squeeze 12 mm bolts (about 15/32") through the rear spring hangers, as the original ones were 7/16" (52" rear springs are symmetrical, so the rear spring eye is same 14mm as the front one).

[Antti]

The front spring eyes are pretty far forward.


The axle is under an inch forward from stock position (notice that tires are steered a bit to the right in the picture). I didn't measure it, but it came out a little bit taller than it was with the old stock length 4" lift springs.


I think that I can go on with the stock steering for a while although the axle can droop pretty low. The shocks run out of length just before the springs reach their full droop. The most critical thing now is the front drive shaft. It's seriously too short, even though I made a 1/2-inch spacer to the transfer case end of it by modifying an old drive shaft flange.

[Antti]

Yesterday I swapped out a bent rear axle shaft for a little better used one. Also put degreeing shims at the rear axle and added the overload springs I removed from the 52" springs to the rear spring packs. Sits pretty level now, but I have to wait after putting the hood and the bed on and driving around a little to see how it'll actually sit. Nothing much to take pictures about really...

Next thing would be the exhaust. Then the cleaning, welding and painting of the bed. Gee, I would like to get her on the road already! Well, at least I'm already done by far the biggest part of the work, and there's nothing really difficult left... but I know everything will always take three times more than I plan (last night's little job I described being a refreshing exception to the rule), so it's best not to schedule anything at all, but just do it a day by day and hope to finish in some time.   

[Just-speed]

You could be a writer you know that?

You do a great job working on the truck as well as describing what you have done. Great thread. Cant wait to read more.

[Antti]

Thank you, Just-speed! What an unexpected compliment, you made my day! 

I can't wait either to have something to write about again...  Seems like it's gonna be weekend at home, so I think I'll get to work on the bed. 

[Antti]

 

[Antti]

I haven't posted for awhile, been pretty busy.

Finally got her on the road. We made a trip to my parents' summer cottage last weekend and the truck functioned ok. I finished w/ the bed just before in a hurry, but I think it turned out ok.






The rear of the truck is sitting too low, and the axle is too forward.

This is a quick photoshop version about how it will hopefully look after I relocate the axle and put on some ~1" "blocks" I have. Just have to get new longer u-bolts...

[Antti]

Seems like there're dozens of other little things to do...

[oldwhity]

Seems like there're dozens of other little things to do...

It never ends eh?