72 454 Quadrajet bolt torque spec

[Randy Krohn]

Anyone know what the torque spec is for the mounting bolts on a Quadrajet on a 1972 454? I went to remove mine thinking I had a gas leak (which I might still have, but that's another issue), and found that the bolts were barely finger-tight!

Thanks!

[Jack H.]

Re: 72 454 Quadrajet bolt torque spec

The nuts/bolts holding the QJet aren't torqued as tight as you'd think! QJet has a pot metal vs. cast iron/steel throttle plate and used a thick 'insulating' gasket. Bottom line, the base of the carb has to absorb heat/cool cycles without 'warping' the base. This means the gasket does much of the task of handling the stress of thermal cycling, hence mounting fasteners have to be appropriately 'loose' to allow the gasket to expand/contract.

Now, to specifically answer your question, the torque spec is given in the AIM book. It's a 2-step process of criss-cross tightening with the first step targeting 24-48 in-lbs (that's only 2-4 ft-lb!) and the final step achieving 120-168 in-lbs (10-14 ft-lbs)...

[Randy Krohn]

Re: 72 454 Quadrajet bolt torque spec

Thanks for the info!