I did not see a lot of info here in a search so.. Do you see any problems down the road using standard head gasket on 400 heads with vents? They are going on a 350.
The cylinders are Siamesed in the 400, so the block can trap steam below the deck between cylinders, this pocket can build up until you get a hot spot and distort the walls and squeezing the pistons and BOOM. The steam holes allow this to vent to the water jacket in the head. When 400's hit the market back in the day, they got a bad rap as Shade tree guys would bolt their HP heads on them and not do the holes, engines would then overheat and go boom. No one liked the 400's. In my opinion they would be fine on a 350, lets see what others say.............
If I remember correctly this way works. You cannot put regular heads on a 400 though. A buddy of mine did it and his car overheated non stop.
He is thinking 400 heads on a 350 so to answer the OPs question it is not a problem. Or you can get 400 head gaskets and use them to mark the steam holes in the block and drill the block. The steam or vent holes in the block are not necessary in an original 350 block so drilling the block would be optional at best. The early 400 had no steam vents, and they did not need to be built by a shade tree mechanic to have heating problems, all you had to do to have a heating problem with one was put a load on it. Like the Corvair GM addressed the problem after the fact. You can use early heads on a 400 by marking and drilling the heads and if you happen onto an early block that is salvageable you can mark and drill the steam holes in the deck and use it. I do not know about any other place in the country but around here a useable 400 block is just your basic unobtainium, they have all been used up by the short track guys. If I could find one cheap (or free) that would clean up @ .030 or less when it came time to freshen my 355 it would become a 377. Built right they will rev until they come apart.
$$$$$$$$$$$$$$$$$$$$$$$$$$$$ The reason the 388 for my Anglia project isn't a 400/406. It's at least 1500.00 for about 20 horsepower. Maybe when I hit the lottery. And to keep the post on topic, you won't have any problems with the 400 heads/350 headgaskets on a 350.
Thanks again everyone. Beaner, you are dead on about the short track guys. They ate those 400's up. I have had these heads for a while and I might as well use them. All the machine work and prep was done by the previous owner so its a no brainer.
I had a 400 short block that was rusted and froze solid in the late '90s. I took it in trade because I figured if nothing else I could salvage the crank. One of the local roundy round guys heard I had it and came by and asked if I would sell it to him. Well I didn't need the crank very bad so I said yea I guess. he said what'll ya take for it then before I could say a word and without even seeing it he said I'll give you 125 and this 4 bolt 350 block (he had it in the back of his truck). I said ya better see it first and showed it too him, He laughed and said,"So do we got a deal?" Well of course we did. LOL
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