Your memory is perfect, on exhaust the top 3 are in oil and the bottom 4 are in water jacket, ask me how I found this out. Make sure and drain all water from the motor before removing any of the bottom exhaust bolts. I've had some success with the permatex 80632 thread sealant, still have 4 of 14 leaking (for the second time) so going to try the permatex 56521. I'm using Sanderson headers on a 354 Industrial motor. I have been using 3/8 x 1" bolts, going to 3/4". Since my radiator sits lower than the motor, I have to use the airlock system to pull vacuum and fill the system with water (after removing the thermostat), when it stops filling, have to remove the temp sensors in the intake manifold and finish filling, replace the thermostat, finish filling. Otherwise I have air pockets which is not a good thing, ask me how I know. So, if I still have a header bolt leaking, it is a real PITA, not to mention it is almost impossible to remove and replace the bolts in the first place. Now back outside to replace the 4 bolts that I removed yesterday, after draining the water.
^^^^Same on the Desoto 330 I am using in my truck. Also, on the Desoto at least, there were a couple of front cover bolts in the water jacket as well.
Good thread, (another one!) I detected some water trails on my '56 354 Chrysler hemi. Saved me a LOT of time I don't have just to find out. Thanks, guys.
The Jalopy Journal
