Topic: 1967 mustang 390 Back Fire Valve

[travnemi]

I was told that the factory sometimes they used a different anti back fire valves and crimped the bottom tube. I was told this was used sometimes on a 1967 mustang 390, is this true?

Thank you for your help,
Travis

[J_Speegle]

What you have there is a 289 backfire valve that has been modified for use on a 390. 

Did the engine plant do this to make it work on your car originally?  Hmm possibly. Never seen the valve modified this way but have seen other parts though it is IMHO very very rare. It was just a lazy worker if done - others would have just installed a rubber cap on that outlet.  Vast majority of the time the workers grabbed the right part.

If you planning on showing the car you need to make the choice of reusing this one (possibly triggering a deduction) or replacing it with the correct unmodified one.

[travnemi]

Thanks Jeff! I just purchased the correct one.