Nailhead guys, do these work?
Found this listing on Ebay, do they work, are they necessary, and will they do any harm?
This listing is for a set of 4 new intake manifold gasket, exhaust crossover portplugs to fit Buick Nailhead engines 1957-1966.
These can plugs can be used with 364, 400, 401, 425 CID Buick Nailhead engines.
Intake manifold and gasket NOT included.
These plugs will prevent the exhaust ports in your intake manifold from boiling the fuel away in your carburetor which then causes a hard starting condition which is common in all Buick Nailhead engines.
Keep your carburetor and fuel cool which will give you an additional 18horsepower and also prevent hard starting.
We also sell the intake manifold gasket in our eBay store, part number 111-103.
The nuts used in this kit are the locking style, which will prevent them from coming loose and falling into your engine.
http://www.ebay.com/itm/1957-1966-Buick-Nailhead-Intake-Manifold-Exhaust-Crossover-Port-Plugs-V8-Engine-/302348884224?fits=Make%3ABuick&hash=item466565d900 :g:SH0AAOSwgv5ZQDO~&vxp=mtr
2 Attachment(s)
Why spend $9.99 for $0.99 worth of common hardware?
Plugging up the heat holes in the intake manifold gasket could be expected to cause warm-up drivability problems. This assumes original stock components are in use.
Buick issued a service bulletin in '55 (attached) for complaints of rough idle, bucking, or missing. The cause was found to be excess flashing left in the cylinder head exhaust crossover passage. The excess flashing blocked off exhaust gas flow same as the bolts would.
Gaskets on cars w/automatic used 1/2" heat holes; synchromesh had 5/8" holes.
It seems the classic way to address vapor lock problems was to concentrate on improving insulation between the carb base and manifold via gaskets or spacers. Claims of added horsepower are not believable. Where is research data to support 18 HP extra?