I copied pasted this from one of my previous posts
AS MARTINSR SAYS IT'S HARDER THAN IT LOOKS. . We saw a early 50's jeep pickup on a blazer chassis at a car show. looked at it and the guy says it was easy. We have a 48 jeepster, It was on a 4 X 4 jeep FC chassis with a SBC, The original jeepster chassis and pickups have the same contour, pickups just longer in the rear. The jeepster needed new brakes , and even new brakes don't stop very well, the front hubs needed repair. total $ 600 parts needed. I found a blazer with a cancered body, 8 wheels-tires , no engine for $ 150. when we started on it We found the 48 has a shorter engine compartment. had to move the engine back 8 in, new motor and trans mounts new drive shafts, new clutch and brake pedal mounting. , steering shaft rework. had to change gas tank, the jeepster is shorter in the rear than a truck. had to rework rear floor, new shock mounting crosmember. The blazer has heaver drive train and front disc. I would reconsider keeping it on a stock frame, upgrade brakes rear end etc.,
Jeep trucks and wagons frames from about 47 thru the 60's are similar. I have had wagons, pickups..an FC pug nose 3/4 ton with wide tread. and still have the jeepster. The blazer is about 1 to 1 1/2 longer wheel base but you can poke it out the front to have bigger clearance for tires. the blazer is also wider, big tires stick out a ways. A frame swap for a blazer is DOABLE JUST MORE WORK THAN A STOCK FRAME WOULD BE.