Exhaust manifold flange spring bolts length?

dave stragand1

New member
Oct 10, 2017
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Hi All,

On a stock 1978 with a 403, how long should the exhaust manifold flange spring bolts be? I had pulled up that they are 3/8-16 x 1 3/4. I had several of those as "HELP" brand so I put them in on one side, and the spring is near completely compressed. Should there be more 'play' in the spring, such as by using a 2" or 2 1/2" bolt? Or should the spring be near completely compressed?

Thanks,

-Dave
1978 Transmode near Pittsburgh
 
Factory ones on my 455 are not fully threaded. You bottom them to the ridge and that sets the tension. Not sure if the Dorman are made that way.
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John Lebetski
Woodstock, IL
77 Eleganza II