How old do you figure these Macks are?

Early 70's to ??
I don't know when they quit making R models

 

The Mack R series was in on-highway production from 1966 thru 2006. Those appear to be RD models which ended production in 2002, so anywhere from 1966-2002. Most likely they are early 90's, just my gut feeling from owning a few of them over the years. The standard R model was discontinued late 90's, and the popularity of the series faded away.

 

My first trucking job was in a 1982 R model.

Ugly enough to be kinda pretty, not very comfortable, but you could run it hard and put it up wet all day every day.

I'd like to fix one up for ATHS shows.

 

I don't think they ever spec'd one I drove for humans that were not midgets..Most uncomfortable truck ever.. But I'm sure there was someone who got their to be room in the cab.. I've just never seen it.

 

Like Brian says, 1966 to mid 2000's. These have to be '68 or newer, with side lights. With the exception of the red and white one, they appear to have the smaller 1 hose air cleaner, indicating the smaller 237 hp motor. The 300's had a bigger air cleaner with 2 hoses or a backwards hood scoop, like the one I drove. The 1st semi I drove was a '75 R-600, 300, 6 speed. The stars and stripes must be a '76. I remember that paint scheme.

 

Hi Mack, that's true, the R600 I drove didn't have that fancy, "conditioned air" ( except for 55 mph with the wing windows and vents open ( R models had a roof vent, I think, plus the side vent) Some of the Macks I saw with the newer dash had big dents where the worn gearshift lever would bang into the dash ( repeatedly)
http://photos.imageevent.com/jctair/rolloffrmodelmack22ftoutside/websize/Mack Summer Beach 040.JPG

 

Macks and Western Stars. No matter how new they are they still look really old lol.