ISO Bobbed bed, body lift blocks 720

[frankendat]

When I kick around these ideas, it is often met with "those are mods that many regret". Anyone have a regret that they would consider passing along? Recoup the investment for you, make the potential regret less painful for me.

[datzenmike]

Body lift. Should be minimal or it starts to look like a body lift 'up skirt' exposing the frame. I did 4" on my 620. Would not want more.

[Stoffregen Motorsports]

Why body lift? Looks or tire fitment? If for looks, ok, but if tire fitment, why not just lift the truck or cut the fenders?

 

Bobbed beds are for crawlers.

[frankendat]

5 hours ago, Stoffregen Motorsports said:

Why body lift? Looks or tire fitment? If for looks, ok, but if tire fitment, why not just lift the truck or cut the fenders?

 

Bobbed beds are for crawlers.

I haul stuff in my truck almost daily, but rarely things requiring the full bed length and they make those "bed extenders" making that last two feet of steel (approx) dead weight most of the time. I was only thinking making the back of the tailgate a few inches past the back of the rear tire (to stay legal)

And even a steep dirt hill in the desert without rocks is enough to drag the bed.

 

The lift is for tire fitment, 235/85R16 I am thinking 2 or 3 inches max. Every suspension lift option explored had negative consequences that overrode the benefit. Did I miss something simple? More vertical wheel travel would be great, but not at the cost of tire wear. The aggressive tread tires I prefer are already over $200 each for off brand, nearly $1000 a set with mount and balance. The need to last at least 30k, 50k would be much better. Aftermarket A-arms for the front, re-arching the rear springs and longer shocks I thought was the go-to right way to do it, but more than one person with this set up reports tire wear in excess of the above standard. 

[ElliotV]

5 hours ago, frankendat said:

I haul stuff in my truck almost daily, but rarely things requiring the full bed length and they make those "bed extenders" making that last two feet of steel (approx) dead weight most of the time. I was only thinking making the back of the tailgate a few inches past the back of the rear tire (to stay legal)

And even a steep dirt hill in the desert without rocks is enough to drag the bed.

 

The lift is for tire fitment, 235/85R16 I am thinking 2 or 3 inches max. Every suspension lift option explored had negative consequences that overrode the benefit. Did I miss something simple? More vertical wheel travel would be great, but not at the cost of tire wear. The aggressive tread tires I prefer are already over $200 each for off brand, nearly $1000 a set with mount and balance. The need to last at least 30k, 50k would be much better. Aftermarket A-arms for the front, re-arching the rear springs and longer shocks I thought was the go-to right way to do it, but more than one person with this set up reports tire wear in excess of the above standard. 

The problem with the lift kit is stuff like the shifters and the steering column have trouble lining up and I did see someone say they had to trim the plastic piece that goes around the shifter and holds the oil pressure and volt gauge.

 

From what I have seen if you get a good lift kit like from calmini or 4x4 parts and you find a good alignment shop you should be fine but I will note most people I saw said do not go for the 3in of lift just do 2in otherwise you do get excessive camber. I believe 4x4 parts also makes and upgraded set of torsion bars with a higher spring rate for those who want to carry more stuff which I will probably do since I want to use my truck as a camping rig and run a roof rack because let's be honest these things look cool with a roof rack.

 

The one though that keeps going through my head is that the hardbody front suspension is nearly identical to the 720 except I think one has longer torsion bars. From the dimensions I have been able to find since I don't have access to 4x4 hardbody parts the hardbody arms are .5in longer then the 720 arms but they use the exact same ball joints and control arm bushings top and bottom(part numbers cross from several sites between hard body trucks and the 720) so in theory they would bolt in.

 

Here are 2 things that I think would be a benefit to running hardbody front ends. One is if you run a d21 differential with the right gear ratio for you they use one size cv axle since one side of the differential is longer due to the offset of the differential you no longer have 2 different cv axles on your truck meaning you can just keep a spare with you on the trail or something and always have one and then you can run easier to find cv axles. The one thing I am unsure about though is the part numbers for the short cv on the 720 is different from the hardbody. I believe this is due to the longer arms more than anything else since all the examples of at least early(86.5-89) trucks have the same automatic hubs that came on the 720. 

 

The second thing is since the hardbody arms are longer they would in theory allow for more travel in the front and there are more lift kits available for a hardbody than the 720 and they had lower gear options and you can get lockers so you can run larger tires without messing up the final drive and well lockers are self explanatory.

 

Just my 2 cents on things to think about and consider.

[datzenmike]

The 720 column has little u joints so it will flex when the body goes up. The shifter will 'sink' down. A transfer case shifter would be a problem. Radiator goes up but hoses won't flex enough so lower the rad position on the radiator support. There's enough slack for brake lines to extend. The rear flex line from the body to the differential can simply be replaced with a longer one. 

[ElliotV]

22 hours ago, datzenmike said:

The 720 column has little u joints so it will flex when the body goes up. The shifter will 'sink' down. A transfer case shifter would be a problem. Radiator goes up but hoses won't flex enough so lower the rad position on the radiator support. There's enough slack for brake lines to extend. The rear flex line from the body to the differential can simply be replaced with a longer one. 

I thought the flex line went from the frame to the rear diff? I know my truck has a breather on the rear diff that goes to the bottom of the bed which would probably need extended.

[datzenmike]

Sure. From the frame on a truck and body from a car.

 

Gas tank filler will need extending also. I had a flatbed so it didn't matter.

[frankendat]

I have been working on the parts rig D21 and considering swapping the front suspension with my 720. I read somewhere that the 90 D21 used the "same CV axles" and assumed (where I often go wrong) that meant the 90 D21 would have a centered front diff. It wasn't until trying to pull the engine that I realized the front diff was offset and the oil pan will not clear the front cross member. Unfortunately, it is comes within a couple of inches of clearing, which was enough for me to fuck with it for most of a day before heading back to town. Now, it will be very difficult to drop the front end with the "loose" engine. The plan is to chop out the firewall to lift the engine and clear the cross member, then cut the frame, take the front end steering/axle/brakes and sort out what will be good to swap, back at my garage. 

 

[frankendat]

On 4/14/2024 at 10:33 PM, ElliotV said:

The problem with the lift kit is stuff like the shifters and the steering column have trouble lining up and I did see someone say they had to trim the plastic piece that goes around the shifter and holds the oil pressure and volt gauge.

 

From what I have seen if you get a good lift kit like from calmini or 4x4 parts and you find a good alignment shop you should be fine but I will note most people I saw said do not go for the 3in of lift just do 2in otherwise you do get excessive camber. I believe 4x4 parts also makes and upgraded set of torsion bars with a higher spring rate for those who want to carry more stuff which I will probably do since I want to use my truck as a camping rig and run a roof rack because let's be honest these things look cool with a roof rack.

 

The one though that keeps going through my head is that the hardbody front suspension is nearly identical to the 720 except I think one has longer torsion bars. From the dimensions I have been able to find since I don't have access to 4x4 hardbody parts the hardbody arms are .5in longer then the 720 arms but they use the exact same ball joints and control arm bushings top and bottom(part numbers cross from several sites between hard body trucks and the 720) so in theory they would bolt in.

 

Here are 2 things that I think would be a benefit to running hardbody front ends. One is if you run a d21 differential with the right gear ratio for you they use one size cv axle since one side of the differential is longer due to the offset of the differential you no longer have 2 different cv axles on your truck meaning you can just keep a spare with you on the trail or something and always have one and then you can run easier to find cv axles. The one thing I am unsure about though is the part numbers for the short cv on the 720 is different from the hardbody. I believe this is due to the longer arms more than anything else since all the examples of at least early(86.5-89) trucks have the same automatic hubs that came on the 720. 

 

The second thing is since the hardbody arms are longer they would in theory allow for more travel in the front and there are more lift kits available for a hardbody than the 720 and they had lower gear options and you can get lockers so you can run larger tires without messing up the final drive and well lockers are self explanatory.

 

Just my 2 cents on things to think about and consider.

Good thoughts. A quick note on automatic hubs, I find them sub standard and wouldn't own a set. People say things like "personal preference" but I have seen enough bad examples where I wouldn't trust them. If you ever intend to engage in any semi-serious off road activities, then automatic hubs are an unnecessary liability. 

[ElliotV]

1 hour ago, frankendat said:

Good thoughts. A quick note on automatic hubs, I find them sub standard and wouldn't own a set. People say things like "personal preference" but I have seen enough bad examples where I wouldn't trust them. If you ever intend to engage in any semi-serious off road activities, then automatic hubs are an unnecessary liability. 

Yep that was one of the first things I did with my truck was get rid of the auto hubs. They still worked but the I feel much better having the manual hubs. That is part of what led me into the whole sticking d21 suspension stuff underneath the truck since the place I got the manual hubs from said they fit a d21

[frankendat]

2 hours ago, ElliotV said:

Yep that was one of the first things I did with my truck was get rid of the auto hubs. They still worked but the I feel much better having the manual hubs. That is part of what led me into the whole sticking d21 suspension stuff underneath the truck since the place I got the manual hubs from said they fit a d21

So you have done the 720/D21 suspension swap?

 

[ElliotV]

12 hours ago, frankendat said:

So you have done the 720/D21 suspension swap?

 

No I have not I have only owned my truck for a few months but I would love to do it to my parts truck because I don't have to worry about having it out of commission since it isn't my daily but from what I can tell it can be done but take that with a grain of salt because I have not gotten my hands on a d21 yet I have been focused on other projects.

[datzenmike]

Have you looked at maybe just swapping the 720 body onto the D21 frame?

[frankendat]

55 minutes ago, datzenmike said:

Have you looked at maybe just swapping the 720 body onto the D21 frame?

Is the D21 considered superior in terms of frame/suspension and steering?

[NC85ST]

1 hour ago, datzenmike said:

Have you looked at maybe just swapping the 720 body onto the D21 frame?

That was my thought too. Didn’t you say you wanted to swap ka into your truck anyway? If both are kc, it might be easier.

[datzenmike]

Brakes are the same as the 720 4 cylinder, VG powered are upgraded. Suspension at least as good. KA is 50% more power and EFI good mileage.

[frankendat]

49 minutes ago, datzenmike said:

Brakes are the same as the 720 4 cylinder, VG powered are upgraded. Suspension at least as good. KA is 50% more power and EFI good mileage.

At this point keeping the entire D21 is challenging. The brakes look superior to the 720. At least the front, they are dual cylinder and fat rotors. And although I am only speaking theory and am open to being proven wrong, all the data I have found suggests the KA is 50% more power OR good mileage (even turboed)

[ElliotV]

5 hours ago, NC85ST said:

That was my thought too. Didn’t you say you wanted to swap ka into your truck anyway? If both are kc, it might be easier.

Really if everything lines up maybe. But the parts truck I bought one of the previous owners put a d21 bed on the 720 frame and it doesn't line up with all but maybe 2 of the original bed mounts and seems to sit higher on the frame than my daily with the right bed on it. Other than that I think it would just be wiring and maybe some firewall cutting required? I think the k24 uses the same trans but not sure if the V6 uses the same trans and if the shifter would be in the same spot.

Edited April 19 by ElliotV

[datzenmike]

KA and Z series engines have the same engine to transmission bolt pattern and alignment, that's it. You can swap engines or transmissions but the KA transmission is much stronger.

 

 I put a 620 cab and flatbed on a 720 frame and everything lines up. Does a 720 fit a D21? don't know. Probably  could be bolted on with a wire feed wrench.

[ElliotV]

3 hours ago, datzenmike said:

KA and Z series engines have the same engine to transmission bolt pattern and alignment, that's it. You can swap engines or transmissions but the KA transmission is much stronger.

 

 I put a 620 cab and flatbed on a 720 frame and everything lines up. Does a 720 fit a D21? don't know. Probably  could be bolted on with a wire feed wrench.

Wire feed wrenches can make anything fit. On the topic of kA transmissions. Could a guy fit the 4x4 transmission with the married case out of a d21 and stick it in front of the divorced case for double t-cases? I have tried looking to see if anyone attempted it but couldn't find anything.

[frankendat]

2 hours ago, ElliotV said:

Wire feed wrenches can make anything fit. On the topic of kA transmissions. Could a guy fit the 4x4 transmission with the married case out of a d21 and stick it in front of the divorced case for double t-cases? I have tried looking to see if anyone attempted it but couldn't find anything.

I think the shift lever on the divorced case would need to be mounted in the bed. I have both and together they would be crazy long, you might be able work out some funky linkage. A final concern is the offsets have to line up, or over

 

Samurai boys double up and the T100 isn't much bigger than the Zuk case. Two datsun divorced (T100) and a shorty 71B could be a way

Edited April 20 by frankendat

[frankendat]

9 hours ago, datzenmike said:

Brakes are the same as the 720 4 cylinder, VG powered are upgraded. Suspension at least as good. KA is 50% more power and EFI good mileage.

The brakes look beefier than the ones on a 720

[ElliotV]

That looks identical to my trucks except that caliper looks to be bigger

[frankendat]

6 hours ago, ElliotV said:

That looks identical to my trucks except that caliper looks to be bigger

bigger/beefier tomato/tomato