Aluminum heads

[blykins]

Since the preliminary verbal thumb-wrestling has taken place, I'll see if I can answer some of the questions.

1. Need to know whether or not it's an FE or SBF.

2. Need to know every single thing about your existing combination. Is this a short block that needs finished? An existing engine that needs an upgrade?

3. Some of the aftermarket heads will only work on some engines. Again, if we're talking about FE's, the Survival and BBM heads out of the box support about 300 cfm of intake flow and both have modern combustion chamber designs. Edelbrock heads, out of the box, will go about 250-260 cfm at best. They have "old-school" combustion chambers, along with 3/8" diameter valve stems.

As has been noted, the Edelbrocks are available in CNC ported flavors from various venders, which increases the flow and also changes some of the inherent flaws of the Edelbrock heads.

The BBM and Survival heads can also be ported.

All of the above heads can be used on a 390/428/427 bore size. The valve spacing lends itself to that.

The CNC Pond heads will only work on a 427 bore size. They are another option for a nice high-performance cylinder head. The combustion chamber is a little old-school, but CNC ported heads will flow about 350 cfm.

4. The combustion chamber sizes vary on all these heads. The Edelbrock heads usually go about 74cc. The way I usually set up the BBM heads will give them 72cc chambers. Barry's head will go 74-75cc.

The Pond heads start at 92cc. That's a big difference and depending on your short block, you could end up with 8:1 compression or 12:1 compression.

Once I have some more information, including camshaft specs, I can steer you more precisely.

5. A 482 with 300 cfm heads will support around 525-550 hp. The 482's that I do with the CNC ported heads will go higher, towards the 600 hp mark.

6. No one uses sodium filled valves anymore, that's a trademark of the 1960's. Modern day valves are 11/32" stem, stainless steel valves. A teflon valve seal is a no-no, as they eventually get brittle with heat. A Viton rubber valve seal is the seal of choice. The current trend is to also use a small diameter valve spring to help with valvetrain weight and response. It's very common to see 1.250" OD valve springs for flat tappet and hydraulic roller camshafts and we have even been using 1.350" OD valve springs from PAC for solid roller camshafts with engines that peak at 8000 rpm.