could I buy heads yet or should I wait

[72dart318]

there is a good set of heads that I have been looking at that are fully ported with a 5 angle valve job. Looks like they have stock rockers but says that they have been fully ported 360 heads. Could I used them with keith balck pistons and do keith blacks need to have a zero deck height?

[72dart318]

There is a another set with a full casting number of 3671587-6 don't know if there any good but they are 2.02 intake and 1.60 exhaust need to be hot tanked.

[rumblefish360]

IMO, you need to wait, heres why.
You don't know where your going yet. In the build up. You need to know where your piston sits. In example using the KB's;
A zero deck flat top piston will yeild a 9.8-1 ratio. As rated by KB with a 72 cc head chamber.. This is steep for 93 octane.
If you get a piston that sits .010 in the hole, the comp drops to 9.6. And thats pump gas freindly. Very.
Now we'll add gasket differences. The above was used with a .039 thickness in mind. If we increase it a tad. lets say .020 to the thickness in addition to the .010 in hole piston, your ratio drops to 9.18.

Now lets run it in reverse.
The first mentioned combo is done with 72 cc head. Are you sure the head has 72cc's? If not, the comp can rocket. With a 70cc head, it's 10.36. A 65cc head is 11.00 - 1.
Are you getting the picture?

Pistons need not be zero deck. If there domed, they may very well need to be machined to fit the head chamber. It is best IMO that a performance street engine run flat top pistons. These are the most flexable because you can run any cc chamber head without concern, allmost. Piston to valve clearance is one problem and the final ratio is the other.

Just get your block/crank/rods and pistons all done and from there you can decided on what you can do. This is all called planning. All of this should have been done and known before you do anything, purchase anything and machined anything. Otherwise, you can be stuck with parts.

[72dart318]

Pistons are going to be keith black flat tops 107s I think. rods are going to be eagle sir rods, crank is going to be magnafluxed and polished for sure maybe grind if needed. I 'am not going to zero deck the pistons how about the O.E.M 70-74 340 heads 3418915 with flat tops.

[dwc43]

Stock X,J, or U heads will be fine for your combo with 2.02's installed. You don't need the fully ported heads for your application yet.

[72dart318]

What about the heads that came off the 360 that are reworked with 2.02 valves installed and 1.60 that have all new parts. Also how much does that usually cost to get done.

[72dart318]

found out that the block needs a .040 overbore. keith blacks makes pistons that fit that right. Do I need to have it balanced externally for the dart that had a 318 in it or should I get it balanced internally for performance reasons and if internally what do I need to get done to rotating assembly.

[MoparMarcIdaho]

If its a steel crank its internal balance.Match your componenents accordingly.

[72dart318]

Its a cast crank 1979 360 motor going to use eale sir rods keith black .040 over flat tops magnaflux crank, then balance the rotateing assembly can the shop just do this if I tell them what I want.

[MoparMarcIdaho]

If it cast crank its external balance.

[dwc43]

The stock heads will be fine with the big valves installed. Any shop should be able to bore and balance a block and assembly or else it's not much of a shop. I would internal balance it. It will last longer and will give you more choices for converters without the need for that goofy flex plate.

[72dart318]

How much horsepower could this combo make. Keith black 107s, eagle sir rods, aeroheads 360 j heads, lunati 280h .480lift both sides, weiand action plus intake, holley 750cfm carb, mopar electronic ignition kit, hooker headers, then all machine work bore, hone, balance assembly. What about reworked stock 360 smog heads with 2.02 intake. ALSO a 100shot of n20.

[dwc43]

Around 400 easy. Loose the nitro unless your using forged pistons. KB's will NOT hold up the added heat and cylinder pressure.

[72dart318]

thats 400 without nitrous right. How much would that be to the wheels.

[rumblefish360]

Figure a 20% loss through drivetrain. I do not know exactly how much it consumes though.
A machine shop can balance it any way you want. Do it internal like DW said.
Use the 915 heads if theres a choice. They will take you real far.

[72dart318]

The machine shop says keith black pistons are good pistons to use so I 'am going with what they say. Also he said they are very strong.

[rumblefish360]

I agree. Watch your timing with them and ring gap.

[dwc43]

Originally Posted by 72dart318

The machine shop says keith black pistons are good pistons to use so I 'am going with what they say. Also he said they are very strong.

THey are good. We have used them in our race engines before, but they are worthless if your using nitro in it. Get forged pistons or leave the bottle off of it if you want it to stay together. Ring gap them at .018 top and about .016 bottom. If it detonates, they wont last long either.