spark plug depth on a 400

[Armyvet25]

Already posted on C body forum but thought I'd ask here too. is the 78 400 a long reach(3/4") plug or the shorter reach? Not a plug preference thread, just want the correct fitment. And it looks like the FSM calls for a long reach which is opposite of what I thought.
1978 400 Newport

 

[Cranky]

Short reach from what I remember...

 

[Armyvet25]

Short reach from what I remember...

that's what i thought

 

[pnora]

3/8 short reach gasket seat. Some 452 heads will take a short plug taper seat.

 

[Vaanth]

Already posted on C body forum but thought I'd ask here too. is the 78 400 a long reach(3/4") plug or the shorter reach? Not a plug preference thread, just want the correct fitment. And it looks like the FSM calls for a long reach which is opposite of what I thought.
1978 400 Newport

FCBO query answered in Post #3 on FCBO.

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