They won't open up unless the engine is under load. You won't be able to get the vacuum low enough without doing some damage to your engine. If you are suspecting that they aren't opening, you will need to do an on the water test with the engine cover open or off to see.
TANDEM AXLE PACKAGE DEAL
LAST PACKAGE AVAILABLE AT THIS PRICE
5 14X5.5 T06 WHEELS W/GUNMETAL INLAY
5 ST215/75R14 KENDA LOADSTAR KR03 RADIALS
STAINLESS CENTER CAPS, LIFETIME CHROME LUGS
MOUNTED, BALANCED & READY TO INSTALL
PM or email me for tire, wheel or package pricing.
CARBURETOR REBUILDING - $125 + PARTS
LED lights, Chrome & Powder Coated Lugs
2 LED 6" BRAKE LIGHTS DELIVERED $25