Dropping new heads on this weekend - I have a bottle of Permatex Ultra Slick assembly lube, can I use this for the head bolts/washers, or should I search for a bottle of ARP moly bolt lube? Anybody have experience?

Dropping new heads on this weekend - I have a bottle of Permatex Ultra Slick assembly lube, can I use this for the head bolts/washers, or should I search for a bottle of ARP moly bolt lube? Anybody have experience?

Dan, for the head bolts you should be using a thread sealing compund. You should be able to pick up some of this at your local auto parts:

http://www.permatex.com/products/Automotive/thread_compounds/a_thread_sealants/auto_Permatex_High_Temperature_Thread_Sealant.htm

Mike

Stock? Highly modified? New bolts? Old bolts? New bolts follow manufacturers instructions. Old bolts I don't recall factory manual for 60s small block specifying anything but sealer on the threads, so that the ones that enter coolant passages don't leak.

Whats really the desired outcome for torquing threaded fasteners is a required clamping force developed by the tension in the fastener. This can vary greatly depending on the friction between the threads and the bolt head. Not impossible to twist the bolt apart and have a major hassle dealing with that.

New bolts new threads lots of roughness; old bolts and threads much of the roughness has been burnished down. I'd be scared to use moly or assembly lube on headbolt threads. If it was me I'd just make sure the threads and friction surfaces are clean and use a smear of Permatex #2 on the threads and a drop of engine oil on the underside of the bolt head and torque per the factory or manufacturers spec.

My $0.02

New bolts with rolled threads - 400hp motor. I like the idea of thread sealant and oil on the washers to get a good torque number.

Big Thanks, hopfully it will be in the car for fathers day..

I always use indianhead on the threads. Hasn't failed me yet.