06-15-2007 11:29 AM #1
Head gasket thickness on a 390
I need some info. I have a 63 390 with 4 barrel heads. The head gaskets I removed were thin metal gaskets. The gaskets that I got with the rebuild kit are about 3 times thicker (.50 thousands verssas .20 thousands) on the original. If I install the thicker gaskets how much compression will I loose? where can I get the thinner gaskets? I called a couple of parts houses and I just confused them. Summit list a ..40 thousands thickness gasket compressed ,but I would prefer to us the thinner metal gasket. I installed forged flat top pistions and I'm guessing my compression to be around 9.5 to 1.
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Here are some 0.020" gaskets, however, one place it says they are steel and another place it says they are copper. Talk to a Summit tech and have him eyeball the pieces before placing the order......
I'm unfamiliar with the 390 chambers and whether or not you have a flat place on the head to make a squish with, but I'd be more concerned with widening the squish clearance with a thicker gasket than I would be about lowering the compression ratio. Maybe one of the other Ford guys on here can elaborate.
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They are called steel shims. I think .017 is the thinest you can get. I run those on my 67 Merc 410 also. Make sure the head and block surfaces are nice and flat. Also, use a head gasket tach spray when installing them. I'll look for my info as soon as I can. Maybe someone else also has the info.
This is just a quick reference.
Fel pro 8554sp
17.09 each here
Seen if there is a part number stamped into the gasket. If they are oem Fords there will be a number. They came in both .015 and .020 thickness.The Mr Gasket steels are .020. There were a few different ones offered from Ford. Most of the 390's used the B9AE-6051-A gaskets that were .015. I have a NOS set of C8AE-6051-B .020's I don't need. They are for the 390/428bore size. If you need them pm me.
I'm ordering the .20 shims from Summit. I just didn't know what to order. they should be here by Friday and I can assemble the engine this weekend. (Another satisfied customer).
I might as well get some more info while I'v got the experts listining. I'm wondering what H.P. I will be running.
I've got a 361 truck block boared to 4.11 this gives me 402 ci with a 390 crank and rods out of a 1963 390, forged flattop pistons,Comp cams 268 cam. I'll run a aluminuim high rise and a 750 holly. Headers and electric fan on the radiator. I'm running what is called four barrell heads off of a 1963 galaxie 500 390. To start with I'll be running the stock points dist and electronic later on all this and a c-6 which I'm hunting for will go in a 66 fairlane.
Can anyone make a wild guess on the rear wheel H.P. Lets hear from the FE experts please .
Thanks for the help and info guys.
I plugged the numbers into my hp calculator program and your looking at about 350 to 360 horsepower with around 400 to 410 ft lbs of torque. Assumming the weight of the Fairlane at around 3500 lbs that will put you down the track at around a 12.7 @ 108. If your car weighs more obviously it will go slower. I think that with that big C6 you'll be running very low 13's consistantly. I would suggest running regular Felpro head gaskets. Your not talking about an 800 horsepower engine in which you would need to get every last bit of power out of the engine by concerning yourself with that last ounce of compression. I'm sure that you want this engine to be reliable as well a fast so stick with the good Felpro's. I'm sure you don't want to be changing head gaskets in that tight Fairlane engine compartment. Good luck.
390 Headgasket thickness
I'd go with the fel pro, I think they compress to .040. I ran them on my 390
back in the day whern they first started putting the o,ring of a sort in them.
In the mid 70's my 390 ran 12:71 @ 105 in a 4000 lbs 57 Ranchero. Not once,
everytime you raced it. Hell of a bracket car at that time. A .060 over 62
block w 6090C heads, Lowriser rods, 2X4 lowrise intake/w 2 500 cfm carter
comp series carbs, Malory points type Distr, and good headers. A FOMOCO
500-324 cam. 10 in converter. Really basic stuff
good luck, Ron BTW, a 10X28 Tire