I'm assembling my oringed 377 and ran into and issue that the ICS Titan self sealing gaskets don't match up. The sealant bead for lower coolant hole towards the bottom between 2 & 4 and 6 & 8 runs below the bottom of my AFR 190 heads. Just great.

Any suggestions on the best method to seal these to prevent leaking coolant? Also the dart little M block is a 400 bore so does it also need the coolant holes drilled in the heads like the factory GM blocks?

 

Odd. I've got the LittleM block, and AFR210 heads with no issues sealing. This is using the Felpro Locwire o-ring head gaskets. The magic goop I use to seal things that don't seal well is Permatex The Right Stuff - like Silicone RTV, but seals tough jobs better (although it's harder to clean off). I'd check w/ AFR & Tilton also. Maybe just swap to some different gaskets now, rather than chancing a fix w/ RTV.