drdave69

A friend has a 1972 with 350/200 quadrajet that keeps backing off the hold down bolts. This is a fresh carb rebuild and we also added lock washers but that doesn't help. We are thinking of adding a little blue Loctite to all 4 bolts or I suggested replacing the bolts with 4 studs and using nyloc nuts. Is there anything else we could try?

lowbuck72

I agree, go with the studs and aircaft nyloc nuts.

gguillot

drdave69

Thanks. We will plan to add 4 studs and lock nuts. I think we'll stay away from the nylon lock nuts due to the engine heat.

leadfoot4

What are you using for a gasket, between the manifold and the carb? Some of those thick, "stacked" aluminum plate/gasket/aluminum plate/gasket heat isolator deals have a LOT of "crush" to them. However the studs and Nylock nuts might also be a good idea.

MelWff

are you sure the threads in the intake havent been stripped?

drdave69

We are using the gasket that has the plastic (I assume it is plastic) insert within the paper/fiber only. I don't believe the threads are stripped because the bolts will tighten.

jeffwebley

Just because the bolts tighten doesn't mean the threads are not worn. Skip the studs and helicoil the holes. Or locktight green and they will never come loose again. Carb bolts don't get torqued very high to begin with.