G'Day,
Plain & Simple fact is that Drum Brakes when Properly Adjusted & in Good Condition are Just as Good as Discs.
However Drums need to be Maintained in that Condition, Regular Adjustment, Cleaning Etc.
Disc Brake Advantages are: Not Affected by Water, Less Tendency to Pull in an Emergency, Less Heat build up & Less Maintainence.
While I have Purchased a Disc Brake Rear Conversion for my Car it was mainly out of Novelty (The Car was a Retirement Present to my Self, An Old Man's Toy if you know what I mean). And I'm Planning on having all the Doo Dads, Bells & Whistles, I can Afford.
Otherwise I would have been quite content to stick with the Rear Drums. I have always found the Disc / Drum Combination on the 69 - 71s to be Excellent even when compared to most modern Disc / Disc Set ups.
I have an Old Friend with a 65 Model, His Car had a Tendency to Pull "Inconsistantly" You never really knew if it was going to Pull or Not.
He's close to Ninety Years of Age and I was a Little concerned that his Reactions weren't as Fast as they used to be, (Neither are Mine for That Matter) so I convinced him to fit a Set of the Later Discs.
I was out with him a Few Weeks after fitting them, when there was a Very Sudden Holt in the Traffic.
After I Swallowed my Heart, I turned to Him as He sat there with a Huge Grin on his Face and Said That was a Good Idea. And we both knew Exactly what I was talking about. There are Perhaps Many things Not to Cheapskate on a Car, But two of the Most Important are Tyres & Brakes.
Regards Tony.M