value pre 74 heat exchangers

[nkotselas]

I'm are that SSI's are extremely sought after, but are the pre 74 heat exchangers worth any money? Is there any way to confirm they are period correct? Anything to watch out for?

Thanks

[techweenie]

try the 911 technical forum for the differences.. it's mainly MFI vs carbs/CIS. but they are worth $150 each and up.