Cam and head questions
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Junior User
Joined: Oct 2004
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Cam and head questions
If you look in my gallery you can see the heads I got recently. These are 406 heads with stainless valves and dual core springs. Now here's the questions:
1. Someone told me I can't run hydraulic lifters because they might not expand fully because of the dual springs.
2. I would need roller lifters because normal lifters would trash the cam in time.
Are these true? If not what are my options? They are really sweet heads and I'd like to put them onto my 74' highboy. Thanks
1. Someone told me I can't run hydraulic lifters because they might not expand fully because of the dual springs.
2. I would need roller lifters because normal lifters would trash the cam in time.
Are these true? If not what are my options? They are really sweet heads and I'd like to put them onto my 74' highboy. Thanks
Cargo Master
Joined: Aug 2000
Posts: 2,931
Likes: 12
From: SW Michigan
cam and heads
BigJohn, someone is feeding you nonsense. Firstly, your heads don't have double springs. You are looking at a single spring with a dampner inside. FWIW, even if you use double springs, you can still use hydralic lifters. Plenty of guys run double springs with 125 lbs or more on the seat and 450lbs over the nose. And they still are running hydralic lifters. And no, you don't need roller lifters unless you have a roller cam. The only problem you may have is that the exhaust valves look larger than stock. Thats not a problem if the exhausts I see in the picture are the 1.65 size. Are you putting these heads on a 360 or a 390 ? You probably should measure the exhaust valves and see what size they are. If you have the 1.72 427 sized exhausts, they will not fit the 4.050 bore. But they look like great heads. Do you have headers and a 4 barrel carb ? If not, the better breathing of the nice heads, may not help power very much. John, are you related to the Ibeling family that made the power steering setup I'm using ? DinosaurFan, on the old work 'puter
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Junior User
Joined: Oct 2004
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I'll grab my calipers from work tommorrow and measure the valve diameter. If they are the 1.72" size, can I bore the engine out to accomodate them? Once done this truck will have headers better cam, carb etc. Gotta rebuild it anyway so might as well do it right. I was originally intending to put these on my 360 and turn that engine into a 410. Thanks for the reply.
Post Fiend
Joined: Jan 2003
Posts: 8,600
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From: Iowa
Originally Posted by big_i80
If they are the 1.72" size, can I bore the engine out to accomodate them?
Then, with your 428 crank, set of short rods, and 428 pistons, you'd have a... 428!
Cargo Master
Joined: Aug 2000
Posts: 2,931
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From: SW Michigan
No, you can't
BigJohn, you can bore large enough to clear the big 1.72 exhaust valve, but you'd have to bore to 4.160, 030 over 428 size, to make enough room. Your cylinderwalls wouldn't be happy that thin. Just for fun, I bolted a narrow head on a 4.11 bore block and turned the empty block over to see if the 1.72 valve would fit. It ran into the bore at about .350 lift. Even if you have the 1.65 exhaust valves, that fit very nicely over the 4.050 bore of a 390 & 360, breathing will be improved if you notch the bores. The intake valves, however, have LOTS of room. A 2.25 or 2.195 intake and 1.65 exhaust combination would do very well on the small bore blocks. DinosaurFan, on the old work 'puter
