Hey All,

Here is the quick and dirty. Got a 66 Val with a torched 170 in it. Just bought a 79 225 to replace it with. I think the 225 will be temporary until I can rebuild the 170 to go back in it. So here is the question.

Which head should I spend the money to rebuild? The 225 head looks like it will be fine as a temporary solution (probably a year or so). The 170 head has 3 seized valves and would definitely need a rebuild.

I would also like to mill the head to raise cr. I remember one of Doug's articles about the later head being better for performance. Also, the later head would have induction hardened seats. Would I loose this hardening due to grinding for new valve seats. Is that even a factor.

So which would be the best head to spend the money on for the long run?

What say you all?

Thanks,

Chris E.

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-76 Cordoba, 360 4bbl
-68 Valiant, 273 2bbl
-67 Dart /6 4bbl, Leaning Tower of Power!!!

Hello,

I may be contrary to most but I like drool tube head...why? Because of what I do with engines. If you were only going to do one head and leave it on, then the later head could well be your choice. But if you, like me, enjoy doing things like swapping cams, then the drool tube head lets you easily change lifters. I KNOW you can swap the lifters by snaking them out of the newer head...but all you need is one to stick a tad and you will be into pulling the head.

I never had leakiig problem around the plugs cause a problem because if I see a leak start I fix it. I also prefer the variety of plugs that can be tried in a drool head as opposed to the peanut plugs. Last, in my opinion the concern over induction hardened is closer to a theoretical concern than an actual one as far as I can tell for my practices. If you do a serious valve job you will cut the hardened area, so why make a head selection on something you are going to remove? Also, how long and how hard are you going to drive the engine? Wearing out the seats may take the rest of your life! If they wear, pop on another head. (I have several heads built and resting for when the urge hits...swapping a head is a morning job, particularly if you use ARP studs). I worry more about needing oil additive for my cam than I ever would for hardened seats.

rock
'64d100

I would use the later head myself, but I hate drool tube heads.

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Official Cookie and Mater Tormentor.

My pick would be the '66 ("drool tube") head. Much easier cam/lifter changes, and much wider selection of spark plugs. The '79 head is heavier than the '66 head, too.

The "later" heads DD mentions as having a slightly improved combustion chamber are '67-up heads. The first year for the '79-style head was '75.

The '73-up heads have induction-hardened exhaust valve seats, but that's not too critical unless you're doing a shoestring-budget buildup; you'd want to have real hard seat inserts installed in whatever head you pick. And even in the case of a shoestring budget, a street slant-6 generally isn't hard on the exhaust valve/seat junction; even with unhardened seats they last a long time.

Milling the head for increased combustion: Sure, but if you can make the time, it'll be much better to measure and calculate first rather than just randomly shaving off any particular amount. You may find you want to mill the block in addition to (or instead of) the head to get the piston deck height and the compression ratio you want.

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