intake manifold end seals

I am sure the pens would help with alignment but I took them out and have had no leakage. Make sure you don't get silicone in your water passages. I would also suggest doing an oil and filter change after the swap just in case anything fell down into the motor when you were cleaning the heads and end rail surfaces. Then to check for leaks I had the motor running and sprayed brake parts cleaner around all the seals. If the RPM's go up then there is a leak.