This is my go to for still shim gaskets.... Add a little extra in the corners to fill the gap. https://www.permatex.com/products/gasketing/gasket-sealants/permatex-form-a-gasket-no-2-sealant/
I replaced the valley pan gasket and used the recommended sealer where applicable, no change in vacuum. I spray starting fluid under the intake and and the rpms rise........how do I check if the intake has an internal crack or leak?
Oh Crap.. I totally missed something here. I did not know or remembered you where chasing a problem ???... I was thinking you where just R&R-ing the intake. What was done to the engine? Did you do an engine overhaul or something? Normally you only run into this if the heads or the block gets decked, and someone forget to make the corrections for the intake alignment.
Yes, the engine was rebuilt by a reputable rebuilder. I bought a new Fel-pro gasket with the composite gaskets that go along with it. I hope that makes up for any milling that put it out of specs......it should be here next week.
That happens.... When you mock up the intake again, Pay close attention to the bolt hole alignment. Should look centered, Not high or low. If it looks wrong to you, it probably is. go with your gut feeling.
I installed the new intake gasket....no leaks. Now, with the new high performance gasket (with the exhaust block off) the choke doesn't heat up. I'm just so frustrated.......
I'm surprised you didn't just open up the holes for the crossover ports? Most folks today delete the old thermal chokes, in favor of electric conversions. Consequently, it's almost standard practice now for manufacture's to eliminate the crossover ports in their gaskets, or at least leave it as an open option. A lot of aftermarket heads have the ports blocked these days as well. Most of it stems from todays fairy water gasoline that boils and evaporates at the drop of a hat, leading to a number of issues and complaints regarding the crossovers.
Any time the block,heads,or a thin type head gasket is used,the heads sit lower to the crank.That being said,a intake might not be parallel to the intake port surface,and some times sit higher and can leave a gap at the bottom of the intake port,causing a small to large leak,this is why some times you cut off the metal from the intake port at the bottom and install .060 soft intake gasket to seal uneven machining,Mrmopartech
