body swap from 720 to 620

[Velvetpants57]

does anyone know or tried to swap a 620 or 520 body onto a 720 frame. i just bought a 720 4x4 extended cab and have realized that i dont like how the 720 looks. now i have acess to a 620 body that is in really good shape but i dont know how hard it will be to plop it onto the 720 frame.

any thougts

Dallas

[Hirns]

Have you done this?

 

Hirns(Aussie)

[]2eDeYe]

Datzenmike has done this, among other things :cool:

 

I'm sure he will post up when he sees this thread.

[Hirns]

The chassis mounting poits are the same, it is a straightforward swap.

When ready I will provide you with the 13 or so steps to complete the job. The hardest part is lifting the cab high enough to clear the air filter, think about your hoist height, shed roof height etc. Alternatively drop the air from the tyres or remove wheels to get the truck as low as possible.

 

Hirns (Aussie)

[RacnJsn95]

Rather than lift the cab over the engine, why couldn't you pull the bed off first, and if need be just roll the frame out from under the cab... Same with the new cab, roll the frame and stuff back under it from the rear, and set it on there before you put the bed on?

[datzenmike]

There were 3 620 and 3 720 frames.(6 if you count the 4X4s separate, the differences were minor, including higher cab and box mounts) Reg cab short bed, reg cab long bed and KC.

 

It will be easier to swap a KC onto a KC frame and a Long onto a long frame. The long bed and the KC are pretty much the same wheel base frame, but for the two front bed mounts. The long bed front mounts are further to the front on the frame because of the longer box/shorter cab. Likewise, the KC are about 11" to the rear on the frame to allow for the longer cab/shorter box. In fact this is what I did... I put my 620 KC onto a '82 720 long bed by moving the two bed mounts back on the frame. All the mounting bolt holes lined up. A KC to a KC would be easier as the 12 gallon gas tank, which is mounted to the frame, has a notch in the top so it fits under the cab on the KC. (I lowered the long bed 15 gallon gas tank and raised the body 4" in order to keep it)

 

I had to remove the steering wheel and lift the cab back and up off the column on the 620. Next time I will cut the column at the steering box. You will want to convert to the 720 column anyway as power steering was available, (nice) and the column is splined and collapses in an accident. Also, it has a U joint so body lifts are easier than that #%@&% 620 one piece.

 

Mine was an '82 2wd so not much difference in weight. The 620s braking system might be a little weak for the heavier 4X4 frame. Every effort should be made to keep the up graded 720 m/c and booster. The 620 calipers were used through '83 when they were again up graded to vented rotors, bigger calipers and 15/16" m/c from the previous 7/8", much much bigger than the 620s 3/4" m/c. I don't know what year you have but keep the brakes.

[rlh57l]

I'm also considering this conversion. Is there any differences between the 4wd and 2wd king cab chassis(mounting points etc).

 

If yes What is different and is 2wd easier to use than a 4wd. (I have access to a 4wd chassis for free.)

[wayno]

If you drop a 521 cab on a 720 frame, the only mount holes that line up are the front ones under the radiator, but that is good, as it centers the front wheels in the wheel well. :rolleyes: The interior mounts, the one by the front door hinge line, and the rear one just in back of the rear seat mount bolts are both off an inch or so. :( wayno