Extended Cab on 620 Long Bed Frame

[Orange620]

Will a 620 extended cab with a short bed, bolt onto a 620 long bed frame?

 

Basically I'd like to put extended cab sheetmetal on a long bed frame. Will it fit directly on?

[datsunaholic]

No. Mods are needed. While the frames are exactly the same length, the KC rear cab mounts are further back, where the longbed front bed mounts are. So cutting and welding is required.

[Orange620]

No. Mods are needed. While the frames are exactly the same length, the KC rear cab mounts are further back, where the longbed front bed mounts are. So cutting and welding is required.

 

So basically its a matter of removing and relocating the aft cab mounts?

[]2eDeYe]

And the fwd bed mounts.

[peanut2425]

while you are doing that you should just lengthen the chassie and combine the extended cab with a long bed, yeah that'd be sweet

[datsunaholic]

Actually I may be mistaken... the cab mounts are in the same place, but the bed mounts aren't. To put a KC cab on a LB frame, you need to RELOCATE the front bed mounts rearward 340mm, and the REAR bed mounts 45.5mm forward.

 

Of course, if you don't intend to install a bed, you just hack the front bed mounts off altogether.

[Orange620]

Actually I may be mistaken... the cab mounts are in the same place, but the bed mounts aren't. To put a KC cab on a LB frame, you need to RELOCATE the front bed mounts rearward 340mm, and the REAR bed mounts 45.5mm forward.

 

Of course, if you don't intend to install a bed, you just hack the front bed mounts off altogether.

 

I'm definitely going to put a short bed on it. I still need to find a tail gate though.

[Llittle_Llama]

the wheel wells are off though arent they?

[datzenmike]

A long box on a KC will be, unless you lengthen the frame and drive shaft.

 

Doug I get 240mm The distance between the two front bed mts on the long box is 524mm the short box is 284mm

[Orange620]

A long box on a KC will be, unless you lengthen the frame and drive shaft.

 

I want to put a KC(79) with a short bed on a long box frame(75). I will also have a driveshaft and 5 speed from the king cab. I'd like to use the 5 speed. Is the rear axle not going to be aligned with the wheel arches on the short box?

[datzenmike]

The KC and it's short box will fit and look fine on the long wheelbase frame. There are two box mounts ahead of the axle on each side of the frame on all 620s. If you have the long box off and measure between the two front mounts they are 524mm (20.63") apart. The KC mounts are 284mm (11.18"). The front box mounts need to be cut off and moved back the difference between these measurements 240mm (9.45") and welded on again. Moving the mounts back will allow the longer cab to fit on the frame in front of them.

 

I've done this! I put my '78 KC onto an '82 long box truck frame. I moved the front box mount on each side back and everything fits.

[datsunaholic]

Seems like a helluva lot of work just to avoid smog, considering there's no guarantee they won't revert smog back to 1968 in the future. It's happened before. Plus you lose the disc brakes.

 

Mike, I checked the 1978 factory manual to get the numbers. It shows the 3 pairs of cab mounts are identical on all 3 frames. It shows the center pairs of bed mounts are also in the same place, at least on the KC and LB frames. But the front bed mount is closer to #2 bed mount, and the rear bed mount is closer to #3 bed mount on the KC frame vs the LB frame. The KC bed mounts are the same distance apart from each other as the SB. There are drawings in the 620 factory manual under Body and Frame.

 

The 720 frames are slightly different in this regard.

[datzenmike]

Agreed!

[Orange620]

Seems like a helluva lot of work just to avoid smog, considering there's no guarantee they won't revert smog back to 1968 in the future. It's happened before. Plus you lose the disc brakes.

 

Its not just a matter of avoiding annual smog checks, its a matter of having the option to modify(or swap) the engine. In California, for 76 and later vehicles, for practical purposes there are no modifications you can make to an engine. For 75 and earlier vehicles, there are no limits to what you can do.

 

I'm seriously impressesed with and greatly appreciate the knowledge and advice I've gotten. With what I've heard, I'm going to take a real hard look at whether its less work to seamlessy replace a section of the top forward frame rail or remove and relocate four bed mounts, the five speed transmission and the front discs.

Edited October 3, 2008 by Orange620

[BarryA]

Its not just a matter of avoiding annual smog checks, its a matter of having the option to modify(or swap) the engine. In California, for 76 and later vehicles, for practical purposes there are no modifications you can make to an engine. For 75 and earlier vehicles, there are no limits to what you can do.

 

I'm seriously impressesed with and greatly appreciate the knowledge and advice I've gotten. With what I've heard, I'm going to take a real hard look at whether its less work to seamlessy replace a section of the top forward frame rail or remove and relocate four bed mounts, the five speed transmission and the front discs.

 

 

some pretty sophisticated methods of checking for welds and alterations when they suspect that a vin has been altered (when they find an altered vin, the consequences usually aren't real pleasant).

 

You might want to take a look in the "Interiors" forum for the "I changed (swapped?) my vin" thread - it's pretty extensive, and goes into some some pretty fine detail on the topic, including a post toward the end that details the vin prefixes for long beds, short beds and king cabs (found out from that post that they're NOT all the same, so a really savvy cop or DMV employee would be able to immediately tell that there was a mismatch in a KC body on a chassis with a long bed vin).

 

I gave the same project some fairly serious thought before buying my 79 KC - personally, if I were going to head in this direction, I'd drop a KC cab on a 75 long bed frame with the original 75 engine still in place and trailer it down to the DMV to try to get a "specially constructed vehicle" vin assigned as a 1975 vehicle. The other alternative would be to install whatever later model engine you were considering, then take it through the "smog referee" program to get the truck smogged to the year/model of the later engine installed - once that's done, you're free and clear (other than having to get the truck smogged every other year).

[datzenmike]

What happens if the frame lettering were illegible from rust.. or .. other?? Seen some that were really bad others I could not find.

[Orange620]

I gave the same project some fairly serious thought before buying my 79 KC - personally, if I were going to head in this direction, I'd drop a KC cab on a 75 long bed frame with the original 75 engine still in place and trailer it down to the DMV to try to get a "specially constructed vehicle" vin assigned as a 1975 vehicle. The other alternative would be to install whatever later model engine you were considering, then take it through the "smog referee" program to get the truck smogged to the year/model of the later engine installed - once that's done, you're free and clear (other than having to get the truck smogged every other year).

 

The 75 long bed is on non-op now. I'll ask a local police officer to do the verification for me. When I get the title in my name, I'll decide how to convert it to a KC. I actually just drove to Ridgecrest today(850 miles round trip) and picked up the KC. It turned out to be a 77 instead of a 79, so no discs or 5 speed,(bummer) but it had been sitting in the open desert since 1988. The interior is toast but the body is great! I think the original orange paint might actually come up with some polish. It is a genuine bullet side though. Its got what looks like several 45 cal. holes through the side of the bed. It was just $150. He's also got a 72 520 for $100.

 

The KC has a nice sliding rear window. Was that standard on KCs?

Edited October 4, 2008 by Orange620

[datzenmike]

Not that I know of.

[BarryA]

Craigslist as far back as July or so. Don't know if you've run across the info yet or not, but one of the guys who posts on this board regularly (Beebani?) was selling custom fabricated upper tubular control arms that allow disc brake/ball joint spindles and lower arms to be used on 77 and earlier trucks.

 

I'm going to be installing Belltech 2" drop hardbody spindles and vented discs on my '79 in the next couple of weeks, so I'll have a complete set of good disc brakes and spindles available shortly if you're interested - I've also got some other surplus stuff form the KC project (including an 80 720 5 speed) you might be able to use....

 

As far as the question about a frame vin that's illegible from rust, I've heard of vins that have been ground off and welded over being brought back - had something to do with the factory frame stampings being punched in so hard that the metal is disturbed well below the surface, and can be still be read after the metal is ground down smooth and treated with some sort of acid.

Edited October 4, 2008 by BarryA
left out a comment

[SickDrift]

I've heard of vins that have been ground off and welded over being brought back - had something to do with the factory frame stampings being punched in so hard that the metal is disturbed well below the surface, and can be still be read after the metal is ground down smooth and treated with some sort of acid.

 

Wow, wtf? That is a whoooooooooole shit load of work to verify the vin on a frame, especially for law enforcement officials. For them to go that far, and through that much effort, they'd have to have quite a bit of motive. For the honda racers I could see this being a concern as so many of these are stolen regularly, but for 30+ year old pickups, I dont think they'd look twice.

 

If smog is a real concern, theres always the option of doing a legal cng modification, and if I understand correctly, once this install is done and ref'd, they reclassify the vehicle as smog exempt. Then I guess you could do what ever you wanted.

 

Anyway, BarryA, I'm not trying to say you're wrong or anything, just that it might not be that much of a problem. I might not even swap vins, but rather keep it all the same since the chassis is smog exempt. Maybe go down and get it OK'd at the CHP claiming that the old body was too damaged to repair, so a different cab has been fitted. They'll just want to run the VIN and make sure the cab isnt stolen, and that all the lights and safety devices operate properly.

[Orange620]

Craigslist as far back as July or so. Don't know if you've run across the info yet or not, but one of the guys who posts on this board regularly (Beebani?) was selling custom fabricated upper tubular control arms that allow disc brake/ball joint spindles and lower arms to be used on 77 and earlier trucks.

 

I'm going to be installing Belltech 2" drop hardbody spindles and vented discs on my '79 in the next couple of weeks, so I'll have a complete set of good disc brakes and spindles available shortly if you're interested - I've also got some other surplus stuff form the KC project (including an 80 720 5 speed) you might be able to use....

 

 

I just saw the Beebani A-arm this evening. I'd like to convert to ball joint/vented discs. I'm going to be looking for an 82-83 ZX 5 speed for the high top gear. The one thing the Fairfield P&P has is lots of ZXs.

[BarryA]

Wow, wtf? That is a whoooooooooole shit load of work to verify the vin on a frame, especially for law enforcement officials. For them to go that far, and through that much effort, they'd have to have quite a bit of motive......

 

More years ago than I like to think about (mid 70's), I damn near lost a VW bug that I had a LOT of work into after a body swap (got sideswiped & replaced the destroyed 63 body shell with a 55 oval window on the existing 63 pan) because the section of the center frame tunnel that has the vin stamped into it had been cut out of the 55 frame and welded into the 63 frame so the numbers would match.

 

Obviously, this had absolutely nothing to do with smog, since the 63 was completely exempt - I got stopped for speeding at 6 am on 101 way up on the CA north coast, and the CHP officer decided to check everything - lights, horn, vin numbers, the works. He threated to arrest me on the spot and impound the car as a stolen vehicle - fortunately, I had the registration for both cars in the glove box, so he just wrote me up for both speeding and an "altered" vin and let me go.

 

According to the DMV, the only reason I didn't lose the car altogether was that I had the pink slips for both cars and both vins were clean, but it still took close to two months and multiple trips to the DMV, getting a new "assigned" vin for the car, and a trip the CHP office to get new assigned vin plates rivited to the frame and body to get it all cleared up.

 

Definately more work and hassle than I ever want to go through again.

[Orange620]

More years ago than I like to think about (mid 70's), I damn near lost a VW bug that I had a LOT of work into after a body swap (got sideswiped & replaced the destroyed 63 body shell with a 55 oval window on the existing 63 pan) because the section of the center frame tunnel that has the vin stamped into it had been cut out of the 55 frame and welded into the 63 frame so the numbers would match.

 

I've read that a couple times but I must be missing something. You say the 63 body got smashed so you swapped a 55 oval window body on to the 63 pan. Then you said you cut the tunnel section out of the 55 pan and welded it onto the 63 pan, "so the frame numbers would match". Match what? They certainly wouldn't match the title of the original 63 VW. Also, why did you take an oval body off a perfectly good 55 pan? I've put oval bodies on IRS pans but yours were both kingpin/swingaxle.

 

Did the CHP write you up because your chassis had been altered or because your chassis number didn't match your registration?

[BarryA]

I've read that a couple times but I must be missing something. You say the 63 body got smashed so you swapped a 55 oval window body on to the 63 pan. Then you said you cut the tunnel section out of the 55 pan and welded it onto the 63 pan, "so the frame numbers would match". Match what? They certainly wouldn't match the title of the original 63 VW. Also, why did you take an oval body off a perfectly good 55 pan? I've put oval bodies on IRS pans but yours were both kingpin/swingaxle.

 

Did the CHP write you up because your chassis had been altered or because your chassis number didn't match your registration?

 

been sitting in a yard outside Arcata for several years with all of the suspension, drivetrain and fenders gone, and a big hole in the right rear corner of the pan where the battery used to live.

 

The 63 had a bunch of work in the suspension (adjustable front beam, re-indexed rear trailing arms, big front sway bar, rear camber compensator, Koni shocks, etc) along with a 67 transaxle, early type 3 rear brakes, short shifter, and no rust.

 

At the time, it made a lot more sense to bring the 55's registration current, swap bodies, and buy a couple of used fenders than it did to move all of the suspension and running gear to the '55 pan (which would also have required changing the shift cone on the front of the transaxle to a bus unit to make the trans fit the early mount). Keeping the 63 registration and plates wasn't a viable option, because with the oval body, it obviously wasn't a '63.

 

Remember, this was about 1972 - early bugs were still all over the place, and weren't worth much. In addition, I was in college, the bug was my only transportation, and I couldn't afford to have it down long. The guy I bought the '55 from had a welder & was willing to shorten and reweld the body mounts where the rear suspension attaches in the rear wheel wells and help me swap bodies, so we moved the pan section with the vin # at the same time, and the car was back on its wheels and running with the 55 body installed in one afternoon.

 

CHP's issue was that the vin # had been changed - title, registration and plates all matched for the '55's numbers, and were current.

[420n620]

I thought this thread was about KC w/ LB

I guess this is what you could call a thread jacking ????????

:bored:

can we get back on to the KC/LB subject --- please

:thumbup: