glord

I am trying to locate a source for a set of exhaust crossover blockoff plates on the 1966 L69 Tri-Carb intake. Both of mine are missing the actual block-off tab or flange. If I cannot locate replacements I will need to weld new flanges to the existing caps so if anyone has a picture of what the original part looks like and/or dimensions of the actual flange that would be very helpful as well.

Thank you in advance for you help, Gary Lord

aliensatemybuick

Gary, if I understand your query, you do have the caps, but the plates that extend down into the crossover runners have broken off. I can say that for regular street use you would likely run the caps in the "open" configuration, i.e. allowing the heat to flow under the center carb and to activate the divorce choke properly. Which means that the missing plates/flanges would not even matter. In the "closed" configuration the flanges would effectively limit the exhaust crossover flow, making the center carb slow to warm up, especially an issue in the colder weather.

A guy by the name of Tom Cook reproed these caps a few years back as I recall, and he may have some extras left over. There MAY have been an issue with the quality of the castings. Amyway, you can try these E-mails to contact him:

tcook@ppg.com
olds442l69@hotmail.com

Good luck! --Scott

glord

Yes Scott that is correct. The issue I'm having is that I'm experiencing what I thought was vapor lock on hot days. This along with the burning of the paint on the intake on either side of the center carb. What I've subsequently learned is that what I thought was vapor lock is likely the gas boiling in the center carb due to the unrestricted exhaust gases coupled with the higher ethanol content of today's fuels. Apparently the latter exacerbates the boiling gas issue.

So, I'm hoping that obtaining a set of intact block-offs and installing them in the closed position will do the trick. This in spite of the fact that I will need to let the car warm up before driving. However, this really is not a problem living in California and for how infrequently I drive the car.

In any case, thank you very much for your post. I will absolutely follow-up with Tom Cook.

Regards, Gary