From a 1968 interview with The Rolling Stone Magazine:

[R.S.]: What does “Disraeli Gears” mean?

[E.C.]: It’s a pun; it doesn’t mean anything. In England there is a big thing on racing cycling and on the back wheel, fixed to the hub you have a gear with ten gears, called a “derailer.” That’s the pun. We were just in a car one night kicking up puns, like Duke Elephant and Elephant Gerald, and “Disraeli Gears” just came up and I said that would be a good name for the record.

[R.S.]: Who’s your producer?

[E.C.]: [Former Mountain bassist] Felix Pappalardi. He’s been working mostly on the folk scene, people like Joan Baez and that. He was just around Atlantic City and said he wanted to do it and we wanted him.

[R.S.]: What kind of guitar and amplifiers do you use?

[E.C.]: A Les Paul, a modern one. A solid one. Same pickups, more or less the same neck, just a different body than the 1958 ones. It’s obviously not as good a sound as the old ones, ’cause they’ve got vintage, like old wine. I haven’t got any old ones still intact, they’ve all gotten broken, warped. When a guitar is that old you’ve got to be careful. There’s a maker, I think it’s Hagstrom or someone like that, that’s copying the old Les Pauls, but I wouldn’t buy one.

[R.S.]: Amps, and how do you set them?

[E.C.]: Two 100-watt Marshalls. I set them full on everything, full treble, full base and full presence, same with the controls on the guitar. If you’ve got the amp and guitar full, there is so much volume that you can get it 100 miles away and it’s going to feed back – the sustaining effect – and anywhere in the vicinity it’s going to feed back.

[R.S.]: Strings?

[E.C.]: Fender rock and roll.

These Fender Rock N’ Roll 150 strings were used by Duane Allman.

This article comes from the June 1978 issue of the Dutch publication Music Maker.

Rory Gallagher: “When I play “Cradle of Rock”, for instance, I don't know if you are familiar with that one, or “Jacknife Beat” I use the Stratocaster with the regular tuning and Fender Rock’n Roll light gauge strings. Playing something like “Bullfrog Blues” I use the Telecaster on which the strings will have the following thicknesses: 013, 015, 020 etc. In any case, thicker strings which produce a richer sound. If I could, I would like to use even thicker strings, but sometimes I tune the guitar in A or E and I use a capo for playing higher tunings. On the acoustical guitar, I take the tuning down to D or G. In that case, I use medium bronze earthwood strings. I always use rough wound strings, and also for playing slide. I know that Lowell George of Little Feat combines ground bass strings with other high strings”.

He wore his Tele high, used light gauge Fender Rock and Roll strings, and would only change them “when they break.”