Ok, so after putting my 484 Hemi together and everything works great, it leaks oil out of the side of the heads. I used a steel shim gasket with no sealant (yes, I know and am now paying the price). So I took the heads off and prepped everything for re-assembly. I am using new steel shim gaskets. What would be the best way to make sure it does not leak again? I like using the "right stuff" gasket maker but not sure it should be used here. Would the permanex copper spray work better? Thanks.

Hylomar spray, light coat on both sides.

I'm sure you don't want to here that the reason it is leaking is do to surfaces that are not flat and parelel to each, or that the surfaces are to rough to seal against the steel head gasket Is this one of Ma Mopar wonderful ( ) replacement blocks with the really oourse deck surfaces? If you drag a fingernail or thumb nail acorss the deck surfaces can you feel the ridges? If so it is way to rough, it needs a smoother, finer surface I ran into this on the first new Mopar Hemi replacement block I built for customer using Cometic head gaskets, it leaked water out of all four corners I had to take it apart and have the deck cut to 50 RA or smoother for those gaskets to seal, which they did very well after that IHTHs

Thanks Cab for the scare, lol.. but this is an original 66/7 block that is a fresh build. Heads and deck are smooth.

Copper Coat

I'm with Cab on this. Something is not right, flatness or machining (assuming it is not something like dowel pins too long) So what your goal is for the sealant to be a good enough band aide to keep it from leaking.

Copper Coat will usually take care of machining roughness.

After most people get a block or heads cut they forget to
check the dowel pins ... I cut them so the head sets flat
with no gasket.... I know.. I forgot to check that 1 time

I will check that first. Good Point.

I am going through this right now. I used the steel shim head gaskets with copper spray coating. I also used the Permatex 2A sealant around the oil return, oil feed and coolant holes. One corner leaked on driver's side front. The other side is sealed up nice and tight. I found the gasket didn't line up with the return holes and oil was seeping where the sealant missed due to offset. Head and block surfaced to square up and get smooth finish.

I am in middle of re-assembling now. Hopefully I will finish up tonight and get a restart later this week.

Been there before and always set the heads on the deck w/no gaskets........

Done it too - dowel pins got me...