Do i need to put some kind of thread sealer on my head bolts?

 

Yes. I use a teflon paste sealer on all of the head bolts and the intake manifold bolts as well. Any auto parts store will have this sealer.

 

Yes.

Every one goes right straight into the water jacket.

Use some kind of non-hardening sealer. NOT silicone, it will leak, guaranteed, every time, sooner or later. (Meaning, if somebody used it and it's working for the moment, it's just a matter of time before it starts leaking) Something like Loctite PST or whatever its number is these days (automotive pipe thread sealer with Teflon) is best, because it makes a great thread lube too as well as sealer. Permatex 200 (the brown goooey glop you brush on) is OK too. Anything that sets up hard, like shellac for example, will eventually break. Silicone tears from all the motion - head bolts move around ALOT over their lifetime.

 

Yeah I used the Loctite PST w/teflon on mine just recently. I think the number was 567. I used silicone sealer years ago, but now I'm older and wiser hopefully! I second the recommendation to use it on your lower intake bolts too. Some of the intake bolts go into the water jacket, and small block chevys are notorious for pumping engine oil past the second intake bolt from the front of the motor too.