how much better is a D8 250cid head over a D7 250cid head. my 250 i got off of ebay which i plan on putting in my falcon has a d7 head on it. the engine in the car is a 79' 200cid i plan on putting a turbo on the 250 which head should i use the 200, 250 D7, or hunt down a D8?
which head is better?
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What is the differance between them, D7 and D8. And what makes it a D7 or D8. Im new Sorry 
D7 should be fine if the price is right. Your not being silly if its in good shape and able to be delivered on your doorstep!
Ford made running changes to its heads more than its engine blocks. So while a 68 Ford 200 is pretty much the same as a 1980 Ford 3.3, the heads had many running changes. Carb changes, emissions gear upgrades, fuel changes to unleaded, reliabilty issus from warranty claims, and engineering plant reshufles all make for revise any XX-6015 XX casting with a new date code and a new revsion code. So there are something like 40 castings around for the 3.3 head!
People like the D8 (Ford code for 1978) head because by then you could be certain the head has the nice big 1.75" intake valves, the nice large runner intake manifold casting, and the hardened valve inserts. They are really well engineered. Some D7's (Ford code for 1977) are just as good as the D8's, but D8's are certain to have all the good bits on them.
Ford was still looking at getting reliable valve seats, and some heads had induction hardened seats (by heating with an electric coil), while some waranty claimes forced Ford to place a kind of hard steel exhast and intake valve insert as a running change.
Ford is really funny. Waranty claim, it'll move hesaven and earth to change any existing component at any time it pleases. If it works, it stasys in production and gets ayearly revison only for emissions
Ford made running changes to its heads more than its engine blocks. So while a 68 Ford 200 is pretty much the same as a 1980 Ford 3.3, the heads had many running changes. Carb changes, emissions gear upgrades, fuel changes to unleaded, reliabilty issus from warranty claims, and engineering plant reshufles all make for revise any XX-6015 XX casting with a new date code and a new revsion code. So there are something like 40 castings around for the 3.3 head!
People like the D8 (Ford code for 1978) head because by then you could be certain the head has the nice big 1.75" intake valves, the nice large runner intake manifold casting, and the hardened valve inserts. They are really well engineered. Some D7's (Ford code for 1977) are just as good as the D8's, but D8's are certain to have all the good bits on them.
Ford was still looking at getting reliable valve seats, and some heads had induction hardened seats (by heating with an electric coil), while some waranty claimes forced Ford to place a kind of hard steel exhast and intake valve insert as a running change.
Ford is really funny. Waranty claim, it'll move hesaven and earth to change any existing component at any time it pleases. If it works, it stasys in production and gets ayearly revison only for emissions
i already have the 250 i got it off ebay complete running motor with every thing for 50 bucks i had to drive 200 miles to pick it up, but hey it was worth it to me. i just took it apart yesterday everything looked ok. i havent taken the short block apart yet hope to do that tomarrow. the cylinder bores are really worn no cross hatches, and a very big lip at the top it might have to go 40 or 60 over to clean up. would the combustion chambers be the same size on the 250 and 200?
