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So I would like to clean up the engine bay on this car. I would also like to get a little more performance out of this 350. Are there plugs available to close up the air ports on these manifolds? Anything removed will be cleaned up and safely stored away. Any thoughts from the experience ones here?
The plugs are a straight National Pipe standard size -- make sure you don't get the more common tapered plug. (I believe they are 1/4" but haven't looked in a long time.) Here's a link to buy a set of plugs, but you may be able to visit the local hardware store and not have to pay shipping. https://corvetteparts.com/item/exhaust-manifold-a-i-r-hole-plug-set
Removing the smog isn’t about any power improvement, it’s just getting a cleaner engine bay. I don’t think it will increase or decrease power at all. Increase would come from a different carb or aftermarket fuel injection. And maybe exhaust as this system looks really old and original. But thank you for your response. All responses are appreciated , positive and negative. Before I do things that I am not familiar with I like to get opinions from those in the know.
If you can swing it, I'd replace the exhaust manifolds with ones without the a.i.r. holes, the water pump pulley with one that does have the pump pulley on it, and the fuel line from the pump to the carb from an application that did not have a smog pump..
Just a thought but if you are getting rid of the smog you might get some decent fun tickets ($) for it. Not quite as valuable pulley-wise as the 350hp L46 but probably worth your time to carefully remove it and sell if you want. Good luck.
Last edited by avalonjohn; Apr 20, 2020 at 10:30 PM.
Yes, I live in California. No I won’t need it to pass inspection. There are no smog checks for any car from 1975 and back. That’s why I play with early cars. All parts removed will be carefully cleaned and stored away. This is a bone stock car. No mods done by original owener.
69 coupe smog delete
