xpoc454

I seem to have picked up a small leak around the bolts of my thermostat hosing.
I have a 427 390 with the aluminum intake.
Are you supposed to use gasket sealer on the threads when tightening down the bolts?

thanks
jim

Mooser

I'm pretty sure at least one (I think both) bolts go into the coolant passage so yes they should have a dab of sealant
M

596

I just replaced my thermostat and gasket. I purchased a reusable aluminum gasket. Both the bolt holes and thermostat hole have rubber gaskets around them on both sides of the gasket. Tightened it down, no mess no fuss, and it works like a charm.

Glad I got the reusable gasket as I believe I'm going to replace the housing this week and I can now just reuse that gasket.

7T1vette

Always! Intake [iron and aluminum] castings can have porosity in them. The wall thickness between the bolt boss and the water jacket isn't very much; and when it is drilled and tapped for the bolt, porosity can easily be opened up. I always put Pernatex gasket sealant on the bottom 3-5 threads on water inlet bolts.

bmans vette

gungatim

I have never had to use sealant on any thermostat housing bolts whether BB or SB, iron or alum. my stock 427 alum. intake just got a new housing last year and it seals just fine with stock gasket. if it's leaking, check the gasket sealing surfaces for flat. people over torque those all the time and they get rusty/cruddy. new housing is $10, or just put it on a flat belt sander to smooth the bottom out.

rdroket