Thermostat - 302

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Parkka

Well-known member
Joined
Jan 12, 2019
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129
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Location
New England
My Car
73 Mustang Convertible
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I have been told by many to drill a 1/8" hole at the upper edge of the thermostat before placing it in the housing to alleviate the initial pressure.  However, the new one I purchased does not have a hole and I cannot find a thermostat for a 73' 302 anywhere with a pre-drilled hole.  There are also no mention of drilling a hole in any of the old repair manuals for the car 

Is this recommended?  If the hole is drilled, what are the consequences?

Thanks,     :thankyouyellow:

Dan

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The idea behind the hole is to allow any air to bleed out of the intake before the t-stat opens. This prevents the initial huge "burp" as the trapped air comes blasting out the top radiator hose.

There is no downside to drilling the hole. Just get a good quality t-stat and do the deed. When you install it, put the hole at the 12 o'clock position.

 
The idea behind the hole is to allow any air to bleed out of the intake before the t-stat opens. This prevents the initial huge "burp" as the trapped air comes blasting out the top radiator hose.

There is no downside to drilling the hole. Just get a good quality t-stat and do the deed. When you install it, put the hole at the 12 o'clock position.
 
the best place to drill the 1/8 in hole is between the "Y". and have it at 12 like mentioned. also if u install with the "Y opening at the top and get a new stat housing with a access hole on top u can put in a temp gage there and not hit anything. so no removal and placement of stat housing once done.

 
thank you.  Never thought about putting a temp gauge there said:
the best place to drill the 1/8 in hole is between the "Y". and have it at 12 like mentioned. also if u install with the "Y opening at the top and get a new stat housing with a access hole on top u can put in a temp gage there and not hit anything. so no removal and placement of stat housing once done.
 
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