Hey there,

On my 2003 hemi I will be putting in a comp cam 260 with 6.1L springs and rods. I noticed when removing my cylinder heads (to put in new lifters) that 8 of the larger M12 head bolts had a paste or sealant on them while 2 came out just oily. I have the service manual and Haynes manual and neither mention the use of thread sealant on the head bolts when reinstalling the heads (I have new head bolts). Engine building sources tell me head bolts through cooling jackets should be coated with thread sealant.

For those that have removed and reinstalled cylinder heads on a hemi, is thread sealant necessary on the head bolts, and if so, in what locations? I made the rookie mistake of not organizing which bolts came out clean and which came out with sealant on the threads.

Thanks guys