I'm replacing the intake manifold gaskets on my 2006 GS300 V6 3.0 l.
the issue is, one side of the new gasket has a slight indentation along the very edge. How do I know which side sits on what surface? I will post pictures to help with my question. Also, should I use silicon gasket maker?? Thank you

Indentation on the inside edge ^



Indentation on the outside edge

 

1) the ABS will take the ridged side. You will see.

2) Don’t use RTV or anything. That’s for when you don’t have a gasket, or extreme angles like on a valve cover on the cam casting.

I like to use a dressing/sealant as insurance and as a tacking compound. Something like Permatex Aviation #3. Brush it on very lightly, use it to position and hold (“tack”) the gasket in place during assembly. This works very well, and has for me for quite a few decades. it will clean off easily, unlike RTV or similar, if you R&R the assembly again.

Pro Tip: once you torque it in place, come back later - as long as you can, overnight even if possible - and re-torque. The gasket will take an initial “set” and then re-retorquing later will really help insure against leaks. This is very effective. This application is not as crucial in that regard, but on pan gaskets, timing cover gaskets, Valve cover gaskets, it is VERY helpful.