The Stovebolt Site Forums The Shop Area General Truck Talk cab differences on 1947 to 1951

I have a 1951 Chevy 3100 its a 3 window cab. I also have a 1947 5 window cab what are the differences between the two cabs? Will the 47 cab bolt on my 51 frame will this be an easy swap if not what do I need to do to make this work?

The differences that come to mind are Vent window in 51. different headliner mounting and different seat movement mechanism and the big one that may present a challenge is the cab mounting. I am sure there are others and someone will be along with more shortly. Jerry

I'm hoping my seat should bolt right in without any mods anybody know ? Looking at the cab mounts differences could I just weld in some cab supports in both rear corners of the 47 then ditch the center mount so I could use cab to frame mounts from my 51? Would it be that easy to do

47/48 had three-point cab mounting, 49+ went to four-point mounting. Fuel tank is at the frame rail 47/48, then moved in-cab on 49. No big deal as long as you want to put the fuel tank in the cab of the 51. There is extra bracing,etc where the fuel tank would go in the early cab, so you can't just pop one in easily. Slightly narrower seat. Vent windows on the newer model doors, but the doors interchange.

When did they ditch the drives side air vent?

1951 when vent windows were introduced.

First, lets identify that you for sure have a 1947, there are some issues in the exchange that may make it harder to accomplish.

1947 unique features:

3 speed on floor, not on column

No provision for column shifter (it has a shallow indentation at the steering mast)

Emergency brake is a lever action next to the shifter on the floor

No emergency brake on the left side.

The gauge cluster is a one year only and will not correctly fit in the later cab and visa versa

The upper cowl does not have the indentation for the water to run off the sides, instead it will overflow into the engine compartment (the engineers missed the mark on this one)

The other features 47/48 are:

Frame mounted gas tank (see other comments)

Body mounts (see other comments)

Windlass crimp moulding

Seat size

There are some additional minor differences, but they will not matter. I think the emergency brake, cab mounts and gauge issue should be addressed before you commit to the swap. None of these should stop you from doing it though. If you are not using a column shifter, then the shallow indentation will not be an issue. The emergency brake can be relocated and you can reuse the parts from your 51 cab. The gauges are probably gong to be reused from the 51 cab so the two lower mounting tabs will have to be relocated to equal proportions (comparing the gauges will make sense)

If it is a 48 cab, the body mounts and the gas tank are the only major changes and the swap will be easier. They corrected the cowl drain system too.

how do I tell if its a 47 or 48?

another way is to use the VIN BUSTER Just type in the serial number found on the drivers side pillar.

For me, the easiest way is to look at the top of the cowl under the hood, if it is smooth with no groove, it's a 47. If it has the drip groove it's 48 or newer. The other easy way is to see where the emergency brake location is. If it's on the left side 48 or newer, if it is located next to the shifter it's a 47. If you have both cabs, look at the indentation for the steering wheel mast, if it is shallow, it's a 47, if it is the same as your 51, it is 48 or newer, if it is barely an indentation, it's a 47……….g

Ok ill look later today but from a pic I have hard to tell but it looks like the cowl under the hood is smooth ill confirm later today thanks for your guys help

So the cowl is flat looks to be a 1947 should I use it or sell it and get a 48 or newer cab?

I can confirm 2 items from your list of 47 differences.
Gauge cluster is different, mounted with screws rather than nuts on studs.
Cowl under hood has no drain channel both on 1947 and 1948 cabs.

The cowl drain system is NOT corrected on the 1948 I have in my "Used truck " lot. Jerry