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Most all I've seen, studs had 5/16-18 course into the manifold, but 5/16-24 up on carb end.
I've used 5/16-18 threaded rod and run it into the manifold to bottom or just smack the thread to snug the rod in the hole ... then used a nylock nut and washer on the carb end. Not too tight, don't want broken ears. I use wheel bearing grease on my carb to manifold gaskets.
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Slideshow: The VelociRaptor Expedition gains a lift, upgraded suspension, Brembo brakes, and trail-ready equipment while retaining the stock 440-horsepower EcoBoost V6.
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