If you don't already have one - Rusty '73-91 Blazers are fairly easy to come by - for around a grand.  This one was pretty sad, even the doors were falling off. (For complete build up - see the '77 Chevy Truck Build up)   Installation is pretty basic - get a whole bunch of guys and take off the extremely heavy metal body and hang the 350-450# NEW FIBERGLASS BODY.
If using the OEM top - line it up on the body and drill the mounting holes.  The cabs rear flange may need to be trimmed off by removing an inch or so, as required. Don't forget to install the fiberglass interior headliner (separate with each body). This may be quite time consuming!
Now drill a small 1" hole in the inner bed side wall to access the nuts you will use to hold the top on.  It takes a professional a day or two to open all the door and window areas and cut the firewall holes for the steering column etc....
Where the original cab seals mount around the door jam, there will be an oversized flange , which will require trimming to match the original metal cab flange inner door mount seal. 
The projects front end was snatched from another truck in the neighborhood (while no one was looking) really from a truck we had on sight.  the front end was secured and hinged and lower pre-split panels installed.  Though not near finished, if you view the before and after photos, you will note the reduced body weight on this vehicle - lifted the suspension about 3 3/4".  If you want a truck to LAST FOREVER this is the way to go. 
NOTE:  Don't be fooled - this project is quite involved and is not intended for the weekend shadetree mechanic.   Inexperience and weak of heart should not attempt this project - or any other project of this size. - we have witnessed what an  unrepairable / irreversible / irreplaceable  mess an amateur can make.

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