I am building up a 390 motor and unfortunately can't afford edel heads but I am wondering if there is a significant difference in stock heads that would fit these fe blocks ? I've heard the 352 heads have bigger exhaust ports. Any info as always is appreciated.
68 F250 4x4
390 np435, np205
rev cut dana 44
35" tires w/ 4" lift
Should throw a pic of this gal on here!
Well, my book says they're standard 352, 390, 410, and 428 heads. 71.2 - 74.2cc chambers. Standard size ports and valves. You'll need hardened exhaust valve seats though, as with all but the D2 heads. The D2's had hardened seats but the hardening was a surface hardening of the head itself, and not very deep. So if they need more than a valve job or two, they'll need the hardened seats installed also.
Speaking of heads, I have a 390/2V out of a 65 Galaxie 500 sitting in a 76F100
waiting for me to get off my butt and finish. While I haven't had a chance to look for casting numbers, it's a safe bet that they were designed for leaded gas. My question is this : how long before a steady diet of unleaded gives me problems ? I ask, as I put over 300,000 miles on a 73F100 with a 302/2V before I burnt 3 valves. Many thanks !
Strider: The "lead" in gas was used to reduce detonation or pinging, not to add lubrication.
I have run unleaded on my C8-AE heads with non-hardened seats for 150K miles, and I spun a bearing before I burned a valve.
The lead tends to form a layer on the valve seat. Once formed, you can go for quite a while on unleaded. However, one valve job and it's gone. After that, expect seats to start sinking in about 20,000 miles.
The reason is that the hot exhaust valve tends to micro-weld itself to the seat. This pulls off tiny chunks of the seat, and blows them out the exhaust. The lead prevents this. Remove the lead, and you remove the protection it provides. Hardened seats resist this micro-welding effect.
or run a lead subsitute but i have c8ae-h and they are great i polished them and did a 3 angle valve job on they and they had 110,000 on the original engine it came out of and only slight marks from not running leaded gas
I think that a good compromise between Edels, and 428CJ iron heads are the C1/C4 heads. With CJ size valves put in them along with hardened seats, and maybe some minor porting and polishing that you would pretty much have at least the equivalent if not better than a 428 CJ head (in terms of flow and cost). They also have a little bit smaller combustion chamber than CJ heads so you wouldn't have to mill them as much depending on your application. The C3 heads would be good to but have a little smaller kidney-bean shaped chamber that is like 67cc and they cost a little more because of that. The C1/C4 heads have the bigger D-shaped chamber that is supposed to be a little smaller than the CJ chambers (I think they average from 72cc to 76cc). Just my .02 cents though.
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