390 cam suggestion

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So your like 4650 ft above sea level. Should factor that in your cam choice.

We must always build for altitude.

Wallace has a couple good calculators that lets us factor in altitude.
 
wilb68 said:
The intake valves are 1.780 and would like flat tappet. Rpm around 1800 to 5000
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I would not bother using those heads. I would not buy any factory heads for use on a stroker. I would use X or Magnums, ONLY IF I had them àlready.... I wouldn't even consider buying them if I didn't.

The amount of money and time it would cost to buy and make them worth it with portung, valves, machining I would ONLY buy new aftermarket heads...which is what I am doing( and I do have my set of magnum heads).

I definitely think the compression is too jhigh for iron heads with that low a poweeband.
 
RustyRatRod said:
Then you certainly need to watch camshaft size. You will easily over cam that engine. In fact, I'd say the factory 340 cam would be to big. Those heads are going to be a real cork with 318 size intake valves. You now are displacing 390 cubes. That was a Ford big block. Get it? You need more cylinder head.
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Agree.
For another example: hipo 396 chevy, with only six more cubes, has a head that flowed DOUBLE the 318 head, 55 years ago.
1.76 (or whatever) intake, that engine will be done at 4500. O.P. will NOT be happy.
 
wilb68 said:
I'm in 4500 altitude
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Oh !!! That's a Big factor to leave out:rolleyes:... Then your compression ratio isn't that high after all. Do you know what castings are the heads? You could have them ported/upgraded...but I still think this is a waste of money vs. $1,200<$1,500 for a set of complete iron heads or $2,000<$2,500 for aluminum.

Regardless, If you get the heads flowing like stock X / Magnum heads you should be able to get in the 375<400hp/430<450 ft-lbs range with and RPm Air-gap and 750 carb, headers, etc. You still didn't mention hyd or solid flat tappet or Roller camshaft? But I would be looking at between 270<280* Degree cams depending on what you choose to do heads wise. Flat tappets will keep you in the .480<.525 lift range. Rollers for will get you in the .525<.575" range depending on rocker ratios.

Nicks garage got 405hp@5,400rpms, 443 lb-ft @4,200 with ported 576 heads w/ 2.02 valves, edelbrock RPm intake and comp 20-227-4 hyd.. flat tappet cam (275/287 adv., 231/237@0.050" lift with .525 valve Lift) 10.5:1 cr 390ci stroker 318.

 
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wilb68 said:
I definitely hear and understand you all that's why I'm here getting your advice. Now dose anyone have a decent set of heads? I can grind my own seats and valves if they need guides i have a guy that can do those. I don't have many mopar guys in my neck of the woods.
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Scour some local yards. I believe the 345 casting is on late 4bbl small blocks. I have run several sets and both machine shops commented on the quality of the castings and exhaust seat. You'll want to run a bowl hog in the intake to open it up a bit.

587 are out there too on 360 motor home engines. Hit your FB market place & craigslist. There too heavy to ship.
 
Perfect I found a set that were on a motor home I'm getting them cleaned up right now.
 
wilb68 said:
Perfect I found a set that were on a motor home I'm getting them cleaned up right now.
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Good luck with your build. If your going hyd cam you'll want a set of good lifters, like Howard's. Your 390 will need some "dwell" to properly fill the cylinders. Call Racer Brown and talk shop...
 

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