Head Gasket Question

I appear to have blown a head gasket on my 400 block today.(I least I didn't blow a seal or .... never mind... you make your own joke) Pulled into the driveway after a 4 mile drive from work, and it was steaming badly. I was about to take Shammoo off the road within the next few weeks anyway.

So my question becomes about the best type of head gasket to use for the rebuild. Any suggestions from you guys?

Dave

Cometic or Fel Pro. Is it just a Head Gasket or did the head crack?

Dave I remember that 400s had a headgasket sealing problem.Sure Nick has more knowledge
on the matter but it seemed to be about the coolant passages getting blocked off by using
the wrong gaskets.I also remember that there is a reverse coolant passages in the heads and
that I believe that FelPro makes a special 400 only gaskets.
Jim

Jim is correct, and if i remeber correctlly you need to make sure the heads have the correct steam passages as well

400 blocks have siamesed cylinder walls that block coolant flow between them.

Do you know if your heads & gaskets have these passages?


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If this is the first you've heard of them, that would be a clue as to why you’re having problems.

- J

Instructions crack me up,"with the head upside down" like where else would you drill the holes?
Jim

My wife doesn't refer to the position of my head as up side down. She uses a different reference point... or hole.

Guys yes I'm aware of the coolant holes vs gasket needs. I am told the more likely culprit may be the need to run a coolant line from the intake manifold above cyl's 4 & 8 to recirculate coolant better to the front again. Seems some manifolds don't allow good crossover or return from there and promotes hot spots.

A motor builder today said he'd take me under his wing to show me how to do it. Sounds like an invitation hard to refuse. Buy him lunch and a few beers for the tutoring lessons.

As always, I'm appreciative of those in my life willing to share hard earned knowledge with me.

On my 406 I ran two lines to the thermostat housing from my cylinder heads between the #4 & #6 and #3 & #5 cylinders right above where the egr ports are on a stock head. This was supposed to eliminate the need for the steam holes (even tho both the gasket and heads had them).
The only problems I ever had with mine was getting the head studs sealed. I tried Teflon (both liquid and tape) different types of rtv and even loctite. Never got them to stop leaking even tho it was just a drop now and then. And I trashed a block torquing a head down and the bolt stripped out which is the reason I went to studs.

Thats been a problem with torquing the headbolts on a 400 since they were first introduced back in the early 70's!
Jim