64" spring swap?

[Mattchu60]

Did you have any issues with pinion angle at all or did it stay pretty close to the same as before. Looks like a pretty strait forward, but time consuming swap.

[redneckwheelman2]

Pinion angle stayed good no driveshaft vibration and I'm not sure if a guy could do it with the big saddle gas tanks or not

[Mattchu60]

My Truck has the 16 gallons tanks (for some reason) instead of the 20s and its a long bed, so there is room for the mounts from what I measured. Assume you drilled new holes for that rear mount then? Just moved it back 2 inches from the stock rear spot?

[redneckwheelman2]

If you have the 56 inch springs stock you shouldnt have to move the rear mounts. Just the front. I wanted to move my axle back so I didn't have to get a custom driveshaft built for my tranny swap. Only reason I moved my rear mounts

[Mattchu60]

Bringing this thread back from the dead. I bought a parts truck a few months ago and spent the last 2 weeks stripping it apart. Body was junk but the frame is solid. Spent quite a few hours grinding off rivets and hammering them out to get the spring brackets off. Working on drilling out new holes in the frame for the longer springs now - its taking quite a while for the drilling. going to try to get some pictures up soon.

[redneckwheelman2]

Yeah all the old rivets had sucked to get out and a few of the new holes sucked to drill out. Especially the ones on the bottom of the frame

[Mattchu60]

hey Redneckwheelman - how do you like the 64"s after driving on them for almost a year? I'm seeing they do lift about 2" from the mockup's I have done, probably do some 2" lift springs in the front as well when its done.

And yes, the bottom rivets were no fun to grind off/pound out.

[redneckwheelman2]

They have been great, they ride 100% better then my friends k20. I think that it's a smoother ride in my 87 then in my 2002 2500hd even.

I have a brand new set of 2 inch Springs and will have a used set sitting in my garage for the front. I'm jumping up to a 4 inch lift since the 8.1L and 9 foot v plow sags the front really bad

[Mattchu60]

A couple pics - this is the day I brought the donor truck home. $300 bucks locally - no motor or transmission. Body was really rough and it sat outside for over 10 years, mice and animals in the cab ruined the interior. The frame is in pretty decent shape which is what i want.



Here is the frame after I removed the body. Has the 14 bolt SF rear end which I'll sell along with the front axle after I am done mocking everything up.

[redneckwheelman2]

So what's the plan with it? Doing a frame swap? I'm just waiting on new u bolts so I can finish my lift up, I'm putting in 3500 Springs now with the top over load plus 2 inch blocks to level it out again.

[Mattchu60]

I just finished moving the spring hangers the other day,we had a bunch of snow the last week so my progress has been slowed down.

I'll try to get some pictures up soon. Plan is to swap the body from my truck over at some point. Project is snowballing now where i am thinking of maybe repainting my body before putting it on which means fixing rust issues first.

[Mattchu60]

Progress update - spring hangers are moved. Today I mocked up the new 16 gallon tanks and mounts. Everything looks good so far - the 16 gallon rear mount needed 2 new holes drilled as it moved it forward on the frame, the front mount stayed in the same spot. Pictures are with the 64" springs on - it does seem to have raised it about 2" from what I can tell - not sure if I'll leave it or use a drop shackle in the future to put it back to stock height.

A few observations I didn't realize - frame is from a 83' K20, my frame is a 87 v10. The 83' frame has a different crossmember under the cab - the 87' version seems to be a little more heavy duty with more bracing. Also the parking brake cable brackets are all different - I ground all the rivets off and removed the brackets for the parking brake on the 83' frame as the 87' version seems much more simple and I'll stick with them.

Also - not sure if this is an k10 vs k20 thing or the years, but the 83' frame is thicker in some places while the 87' appears to have sections which are thinner (almost like parts were cut out under the bed area) - the 83' version seems heavier duty.

This is all surprising to me as I always believed the 81-87 / k10 & k20 frames were all the same before this, finding some small differences in them.

[redneckwheelman2]

About the frame differences. I had looked up my rpo codes when I was redoing mine and there is a regular duty 3/4 ton and a "heavy duty" which had like a 1/16th inch thicker frame the extra braces on the cross members are a k20 only thing I think. k10 didn't have them. But not extremely sure. I had gained about another 1 or 2 inches with swapping to the 3500 rear Springs surprisingly

That's also interesting on how much clearance there is for the gas tank since I never mocked up saddle tanks on mine, since I'm building up toolboxes for where the tanks where originally

[Mattchu60]

With the saddle tanks - it will not work with the 20 gallon tanks - I mocked it up with a 20 gallon tank and its too long to work. Need to use the 16 gallons if anyone wanted to try this.

[Mattchu60]

Well Folks I got the frame sandblasted, primed and painted. Mounted up the brackets with 7/16" fine thread grade 8 bolts before the black paint went on today.

Now I am done with this for the time being - I am looking for a nice rust-free (low-rust) original donor truck, or one which was recently restored (body fixed up, painted well) which I'll swap onto this frame. OR I may swap my truck onto it, which has some rust creeping in which would need to be repaired and its due for a paint job itself. Decisions, decisions.....

[Half Assed]

Speaking of a soft ride, I was thinking of using 54" rear springs from a 95-99 tahoe in place of the front 47" leafs on my 4x4 conversion.

The offroading guys flip the front hangars around and use 52" rears in the front, but that moves the axle forward 2-3". The 54" springs might be a good fit to keep the axle in the same place with flipped hangars. They might give a few inches of lift though.

I haven't torn apart my parts truck to get some better measurements yet . I'd love to put some 64" springs in also, but the saddle tank situation kinda sucks. The ride with 64s is amazing.

[Mattchu60]

Wanted to update on this thread. After many months of work I got my truck body swapped over to my rebuilt frame with the 64" rear springs. Took a drive last night and initial impressions of the ride are very good. Very happy with the results, going to do some more drives in the next few days but I think this was worth the effort.

[jhama78]

Originally Posted by Mattchu60

Wanted to update on this thread. After many months of work I got my truck body swapped over to my rebuilt frame with the 64" rear springs. Took a drive last night and initial impressions of the ride are very good. Very happy with the results, going to do some more drives in the next few days but I think this was worth the effort.

Lets hear some impressions after 6 more months, how far forward did you move the front spring hangers? I've got a set of 64s laying around from a rock crawler project I parted out and my 86 needs a better ride and a little altitude adjustment.

[Mattchu60]

Impressions are very good. The rears soak up bumps much better and I still have the same load capacity as before. I'm really happy with it. For reference, I used the light duty 3/4 ton springs - I believe they have around 2000 lb capacity per leaf.

I had to move the front mounts forward exactly 6" from the stock location. I used lowering shackles on the rear mount to level the truck out, otherwise you get about 2" lift from them

I think on a 2wd truck (no front leafs) it would be amazing, it would feel like a modern machine.

[jhama78]

Originally Posted by Mattchu60

Impressions are very good. The rears soak up bumps much better and I still have the same load capacity as before. I'm really happy with it. For reference, I used the light duty 3/4 ton springs - I believe they have around 2000 lb capacity per leaf.

I had to move the front mounts forward exactly 6" from the stock location. I used lowering shackles on the rear mount to level the truck out, otherwise you get about 2" lift from them

I think on a 2wd truck (no front leafs) it would be amazing, it would feel like a modern machine.

Thanks for the reply, your truck/frame had the 56" rear springs to start with correct?

I plan to lift my truck 2-3 " so it sounds like 64s with no lowering shackle will be about perfect.

[Mattchu60]

My truck had 52" springs on it before - they were the heavy duty version - i think they were around 2100 lbs per leaf capacity - the shorter spring with higher load made it pretty stiff.

I did use the 56" rear spring hanger location - the one farthest back - for the 64s and that worked great.

Note - you can only use the 16 gallon tanks with this - the 20's will not work.

[jhama78]

Originally Posted by Mattchu60

My truck had 52" springs on it before - they were the heavy duty version - i think they were around 2100 lbs per leaf capacity - the shorter spring with higher load made it pretty stiff.

I did use the 56" rear spring hanger location - the one farthest back - for the 64s and that worked great.

Note - you can only use the 16 gallon tanks with this - the 20's will not work.

Great, thanks for the info. My truck is a SWB so it already has 16Gal tanks.

[Mattchu60]

If you have a Short-bed I don't think this would work - its likely you don't have enough room for the hangers to move forward and possible not enough room to move the rears back the needed 4" as well. I would suggest measuring to see how it looks before you start into this.

[jhama78]

Originally Posted by Mattchu60

If you have a Short-bed I don't think this would work - its likely you don't have enough room for the hangers to move forward and possible not enough room to move the rears back the needed 4" as well. I would suggest measuring to see how it looks before you start into this.

I definitely plan to, I know that the off road K5 guys run 64s so maybe there is a way.

[rgunlock]

Keeping an eye on how this goes for you j-rod. Would be nice to know if this is an option for my SWB K15.