Yeah,I had that wagon from 1987 to 1995,I bought it from a friend who drove it home in stock form from St.Cloud FL,it had a 250 straight six and a powerglide ,and a radio delete panel in the dash!..he had a '69 Suburban K10 and it was getting too rotted for street use,one day when the wagon was parked next to it,a light went off in his head and he said "ya know,I have always liked the 4x4 El-Caminos guys put on 4x4 chassis--maybe I'll do that to the wagon!..
A few months later,it was all done,and his son was driving it all over the place--the guy was a long time body and frame man,so cutting the frame to get the wheelbase correct was childs play for him...he put chevy vega bumpers under the Chevelle's in order to meet NH height restrictions,and all the original body mounts on the wagon were retained and bolted to the chassis just as they did on the stock frame...
The car had a 4 bolt 350 from the Suburban that was very tired when I bought it--I swapped inm a 1973 454 from an Impala my older brother owned that was rotted out,it ran sweet,had a fresh valve job and a new Holley q-jet replacement sprread bore carb on it...I kept the TH350 in it,it had a Rockwell divorced T-case from the Suburban in it too..sounded like it had a blower with those whiney straight cut gears in it!..it got a lot of looks at car shows and when just putting around in it...I was tempted to put a plow setup on it,but decided against getting it salty!..