Thermostat neck from Billet Technologies

chasb said

I have a small leak around the bottom of the the thermostat neck on my 440 Dart. I know this is a common problem. I had the motor rebuilt over the winter last year and the new manifold is an Edelbrock performer series aluminum manifold. I am going to try the Billet technologies aluminum t-neck with the rubber o ring seal as I have seen it recommended here and there.

Questions I have are as follows.

1. Since no gasket is needed with this do I still use RtF anywhere?

2. Do I use silicon or some other sealant on the bolt threads?

Click to expand...

Here is my $0.02.
No sealant necessary. I actually have that exact housing from Billet Tech. I had leak problems for a long time, but the Billet Tech housing fixed the problem. I did, however, take a file and then a sanding block to the manifold surface to make sure it was as flat as possible. No matter what some of the people in the above posts said, you do need to make sure that surface is as flat as possible. Think about it. you had a leak, right. The leak could have been all from the housing, all from the manifold, or some of both. Why take a risk that some of your problem was with the manifold surface and not address it. By buying the new housing AND flattening the manifold surface you will be assured to stop the leak.