Make sure the cap and rotor match

[340six]

And a kinda heads up on this brand.
I normally use vintage parts as I stashed away plenty.
But I gave my last 2 old stock Srandard branded Blue Streak Caps and Rotors I had for use with blue colored wires to a friend. He replaced them with new United Motor Products ones. The rotors work with their caps only, and will destroy all the other brand caps oi have.
They sit high on the shaft. You can see the pen mark on the 2 rotors that's a big difference

 

[340six]

On picture 3 you can clearly see it has 3 extra places where there is plastic that make it sit high on the shaft verses the one lug to locate the rotor on the white one.

 

[halifaxhops]

I just did a article on these they often mix up the ch-303 and CH-308 rotors. That taller one is the later one more common in late 70's.
Never saw that make before where did he buy it?
Ignition Rotors

 

[340six]

I just did a article on these they often mix up the ch-303 and CH-308 rotors. That taller one is the later one more common in late 70's.
Never saw that make before where did he buy it?
Ignition Rotors

Rockauto and others has the United Motor Products says made USA. The rotor is fine if used with cap they make I show. Reason I posted pics of boxes with part numbers.
They must be used a a,set. That rotor used on any other cap will wrecks it ASAP. And I tried many none worked other than the cap United makes.
I put the rotors in the boxes with the caps along with a,note to only use with that cap. And Put them on a shelf for Rainey Day. But have lots of vintage to use before that may ever happen.

 

[67Dart273]

They are either wrong part number, packaged wrong, or just plain manufactured out of spec. NEVER in the old days did I ever worry about "matching" brands, etc on parts such as this

 

[halifaxhops]

Rockauto and others has the United Motor Products says made USA. The rotor is fine if used with cap they make I show. Reason I posted pics of boxes with part numbers.
They must be used a a,set. That rotor used on any other cap will wrecks it ASAP. And I tried many none worked other than the cap United makes.
I put the rotors in the boxes with the caps along with a,note to only use with that cap. And Put them on a shelf for Rainey Day. But have lots of vintage to use before that may ever happen.

I really hate the new stuff, to mant stupid issues like that one. Glad you posted it

 

[340six]

They are either wrong part number, packaged wrong, or just plain manufactured out of spec. NEVER in the old days did I ever worry about "matching" brands, etc on parts such as this

It looks like the United cap and their rotor work with each other only.
Use of rotor with another cap destroys it. Use of the cap with a normal rotor from one of the many company's that make rotors would place the contact of the normal rotor very far away from the contacts on the United Cap also not good. We all know how that will work out.
I will say it does look like used as a matched set would be A Ok.
And looks like Halifahops saw this same thing in another brand as well.0
Best to stick with old known good parts if at all possible.
He seems to have good stock as well as some auction sites. Worth the extra bucks for tried and true Known Old Good Parts.
Old Neihoff, Standard Motor Product's, Napa , Mopar etc,are going to dry up so stock up on at least a few.
If someone would have told you-me 40 years ago be careful buying spark plugs they are counterfeit ones out there. You woud have laughed. As time passes things are only going to get worse