73 440 manifold bolt size needed

[RDF]

I need to know the manifold bolt size for my 440 in my 73 Cuda.  Does anyone know?  I'm attempting to put Hedman Headers on it (Part #78036) and need bolts.  When I look online, I see there are many different sizes, ranging from 5/16-18 X 3/4 to 3/8-16 X 3/4.  Not too sure which to get.  I've also seen studs, which I've heard good and bad things about but again, not too sure on size.

[1 Wild R/T]

Small blocks are 5/16-18 but a 440 is a big block & uses a 3/8-18  And since the OE studs go into the water jacket I generally use studs so the water stays in the block if I need to replace a header gasket....

If your running aluminum heads this doesn't apply... But then I prefer studs so I thread the studs in with no load and when I tighten the nuts securing the header the thread contact is steel on steel...

[RDF]

Small blocks are 5/16-18 but a 440 is a big block & uses a 3/8-18  And since the OE studs go into the water jacket I generally use studs so the water stays in the block if I need to replace a header gasket....

If your running aluminum heads this doesn't apply... But then I prefer studs so I thread the studs in with no load and when I tighten the nuts securing the header the thread contact is steel on steel...

Awesome!  I'm running steel heads so I'll go the Stud route, that way i can hang thr header on them and the gasket too.

Thanks a bunch!