I agree with O1GT the difference will be very minimal.
Fender would not market saddles,block etc. on their top of the line assembly line strat that were that inferior. just my .02
this has been a very educational post for me though.

The term transient response is normally used in electronics describing a circuit's ability to react to changes of input and output but it's meaning also has value being used to describe some kinds of physical properties. When straying from discussions of electronics most people will modify the term to dynamic response. I could be wrong about this but I do not believe there is an official scientific term known as dynamic response but many people in various scientific communities do use the term from time to time and I expect it may soon have an official definition. Basically dynamic response refers to any physical system's ability to react to changes of input or output. It is the immediacy of the reaction which is the subject of concern to this terminology. How fast and how accurately does the system respond? In the case of guitars and any other stringed instruments the term would be used to describe how "alive" the instrument is. For Fender instruments it would be a part of the aspect of tone we call spank among other words we commonly use to describe tone. Like you I am also not an engineer and this is pretty much the limit of my ability to describe dynamic response because my own understanding of the term is limited. I am a relative newbie when it comes to this kind of thing. I hope I was able to help you get at least a glimpse of it.

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Just think of how awesome a guitar player you could have been by now if you had only spent the last 10 years practicing instead of obsessing over pickups and roasted maple necks.

You may recall approximately 15 years ago or so that Hartke introduced a line of bass cabinets called transient attack. Maybe it was more than 15 years. Their ad copy for that line of cabinets was the catalyst that got me interested in this subject but I never went very far with it.

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Just think of how awesome a guitar player you could have been by now if you had only spent the last 10 years practicing instead of obsessing over pickups and roasted maple necks.

The blocks in most Vintage reissue Fenders are made out of a free machining alloy, which as Callaham points out, has lead in it so that it drills, taps, and cuts more easily. It also has a less resonant, dampening quality.

Unfortunately Mr. Callaham uses a cold rolled steel but does not anneal, reharden and temper it to a specific hardness. I think the Callaham block is a step ahead but by no means really right.

I've discussed this with Mr. Callaham, but he is a somewhat intransigent fellow. If HE didn't think of an idea, well, he tends to stick his nose up at it. A lot of people from Virginia are like this, I've found. Still, I like his parts better than Vintique for the most part.

I don't think that anyone paid attention to this issue at Fender or anywhere else before Callaham, to tell you the truth. Back in the late 70s, people were putting brass hardware, everything made of brass, on guitars. Bridges, pickguards, jack plates, everything. The mantra was "Improves Sustain". Well, it made a lot of previously good sounding guitars sound lousy and added weight, but the brass trem blocks and bridge plates WERE better than the one piece pot metal cast garbage CBS was putting on the Strats du jour. When Fender did the reissues the Fender steel block went on a lot of earlier guitars, and it was an improvement over the pot metal.


I very seriously doubt whether much research or experimentation went into the precise alloy or hardness in the vintage days, they used what was convenient. When the reissues were done they did likewise. And though the free machining steel is definitely not as good as a classic carbon steel, those early reissue Strats did sound pretty good, better than a lot of vintage ones-and they had the handicap of a urethane bottom coat under the nitro as well. For all their flaws they were much more consistent than the originals.

The company 'yadayada' when the new American Standards were released recently was that they listened to scores of opinions and suggestions which resulted in the copper infused mass block and return to vintage saddles among the other changes they made. The rationale for that choice has never been made cleared but I am sure that there are production and cost issues basic to the final decision.

If the Callaham design, as you have said, still does not rise to the occasion, then your position above likely resolves the issues. That is basically a 'juice vs squeeze' outcome. Most opinions expressed regarding the upgrade see it more beneficial to the MIM guitars and, knowing the nature of that stock mass block, quite understandable.

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"Another day in paradise!"