I want to change over from the hard vacuum lines to silicone lines. Will the silicone lines collapse from the vacuum and the heat or should I stay with the hard lines.

I tried silicone vacuum hoses once I won't do it again.They are suppose to stand up to the heat but if they get against the intake manifold they melt.I went with stainless steel braided hoses and used heavy heat shrink on the ends .

Which lines are hard? Most of mine are rubber. That was stock. Maybe I'm not thinking of the same lines as you?

Jack

Vacuum hoses are designed not to collapse under vacuum. I replaced nearly all of my old brittle hard lines with rubber ones. Save the elbows and other connections leaving some hard line stubs to connect the rubber ones. Or you can use some brass tubbing available at hobby stores to serve as connectors to the elbows.

Doug