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No clearance issues.  I just had to change the spark plug wire ends to female.
  I don't know if it has the high temp bushing, I can't tell if it's removable

Is there a clearance problem when replacing the CRT Pro Series Thunderbird female cap with the MSD 84335/84336 cap on a 55-57 Tbird?   

MSD sells a separate HEI Low Resistance carbon rotor button (part no. 8412) that claims to reduce excessive heat buildup that can melt the distributor cap. does the 84335/84336 cap have the low-resistance button? The button can be installed in an MSD cap that has a spring-loaded button, but the cost is $25-$28.                                                   

Update:  I purchased another Chinese cap from Amazon to see if the new coil and module were the problem, since the MSD is about $75 I didn't want to sacrifice it.   The Amazon cap was made like the CRT, no spring loaded rotor button/contact.  This one wore out like the CRT's. 

I have since installed the MSD cap and rotor and they are working as expected. 

I installed the rotor as described on the measurement card.   I noticed the contact on the rotor bends more easily than the CRT, so I assume it puts a lot less pressure on the cap/button.   The cap/button is also spring loaded NOT fixed like the CRT.   The light metal contact and spring loaded button seem to have fixed the issue.................... 

The top of the cap is embossed (like the rotor) "MSD"

Thanks for the pics, there is no manufacturer's mark in the cap but that doesn't mean is won't be a good product. It does have an ozone vent and with the included instructions to insure the rotor spring is set right shows they are trying to get it right....we'll see.

64F100 57FAIRLANE500

This is the CRT cap (with semi worn button):




This is the MSD cap (has a vent):

They are making an attempt to address the mismatched/anything goes ignition parts being sold these days - this is encouraging. Would you post a picture of the inside area of the cap showing the conductive posts and carbon brush?  MSD is cast on the top surface but years ago, the quality manufacturers used to  cast in their "hall mark."  Just curious if MSD has any marking as such in there....

64F100 57FAIRLANE500

The MSD rotor arrived yesterday.  There is a tag attached to it to measure and adjust the tang.  I have never seen a spec for tang height, I never bought an MSD rotor before.

Part number for rotor 8467, cap 84333 (black) 8433 (red)

I forgot about Pertronix and all related components. What limits a lot of choices here is it's a mechanical tach vehicle. I have found Pertronix 2 with the Pertronix 1.5 ohm coil works good without resistor.  Eliminating the resistor increased the spark energy significantly.  I'm not at home this week to check my notes. However, if anyone is interested, I would be willing to set those components in motion just to produce some real time current and temperature numbers when I can. Sorry for straying away from the thread because to my knowledge, Pertronix does not offer a tach drive distributor. 

64F100 57FAIRLANE500