No, the insulator blocks are meant for 7MM IGN WIRES. You will have to modify for 8MM.
There are quality 7MM wires available.

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Another question, not having really gotten to inspect the Y block, spark plug rating looms, will an 8 mm plug fit inside of them? I bought new plugs but when they showed up, they look significantly larger than what’s on the engine. I don’t think they will fit Inside those rubber blocks. Is it an optical illusion?
Well, enough silicone spray get them to go through? Should I just use thinner stick replacement wires?

Ted Eaton tested one 2-3 years ago and posted the results; the outcome was favorable. I later asked him if he were to choose between the 57 Ford Thunderbird tach-drive distributor and the CRT, which would he choose; he replied, "the CRT". If you go back 2-3 years, you should find Ted's post. See, also Florida_Phil post "New Thunderbird Tach-Drive Distributor Questions" from three years ago. There are two links for Ted's original posts.
 The CRT comes with several different advance springs and adjustable vacuum advance. Their tach-drive distributor will accommodate either mechanical or electric tach.  

Make sure that there will not be any clearance issues for your application.  

Although CRT sells on eBay, you can buy directly from CRT; I did, paid no sales tax, and shipping was free. I haven't installed mine yet; my 55 Tbird is undergoing a slow restoration.

As I slowly MAYBE make progress diagnosing the stumble in my 292, I am wondering about that old adage that says “90% of fuel problems are ignition problems.”
I have a Pertronix Ignitor (first series) now but a long time ago had a bad experience with an Ignitor 2. Conversely, I have run the cheapest imported HEI dizzy in the past and never had a problem…

Looking at maybe trying out one if the CRT units. They don’t look obnoxious- they look like they belong, and HEI has always worked for me. Anyone here have real world experience? I can never get the search feature to work.

Thanks.