Listen; work the formula in reverse.
The La engines have a spec deck height of 9.600. This was the designed height from the top of the block to the center of the crank saddles.
The rod lengths had a spec-length of 6.123
For a 360 cuber the crank had a spec of 3.58 stroke. That means, that from the crank's closest position to the deck, to it's furthest away position from the deck, this was specified to be 3.58 inches.
The compression distance of a piston is the exact distance between the center of the wrist-pin to the flat portion of the crown of the piston, irrespective of any dome/dish/or quenchpad.
So with the definitions out of the way;
To determine the compression distance of any piston, to get to a Zero deck, according to the SPEC, here's what you do;
Yo add half the stroke to all of the rod, then subtract that from the spec deck height.
So for the the 360, half the stroke is 3.58/2=1.79, therefore;
9.600 less (1.79+6.123)= a required compression distance of 1.687 to zero-deck height..... to satisfy the specs.
the KB107s have an advertised cd (compression distance) of 1.675, therefore, they will be 1.687 less 1.675= .012 below the deck, if all the parts are on the spec.
If you want them to be at Zero deck;
Either cut the decks down, buy longer rods, or increase the stroke by double the deck-clearance difference, which is 2 x .012= .024, and .024 plus 3.58=3.604 stroke.
Now; all of this, assumes that the parts that you have or buy are on the design spec.
You cannot know this until you have measured everything. And if what you measure is not on spec, then you have to make machining corrections, or change your engineering requirements.
By far, the cheapest correction is by maching the decks to fit what you have.
But I gotta tell ya, if you are running open chamber heads, taking .012 off the decks is pretty much a waste of money.
To take advantage og Quench you must use a closed-chamber design, to get the Q into a ballpark of .035 plus/minus .015./
If your pistons, in truth, come up to .012 below the deck, then your gasket would need to be that much thinner, to drop the head lower. so then, .035 less .012=.023. Adding the tolerance of .015, equals .038. So your headgasket needs to be in the range of .023 to .038. to satisfy the Q requirement....... if the pistons come to .012 below the physical decks, not the specifications.
When you contemplate installing stroker cranks, you almost always HAVE to buy the Matching Pistons. The stock-spec'ed cd distance pistons, may pop up out of the holes beyond what any open chamber cylinder heads can accept, or at least to the max.
For instance; with a 3.79 stroke, the cd for a spec-deck of 9.600 is
9.600 less( 6.123 plus half of 3.79) equals 1.582... and 1.675(the kb107s) being taller than that, will pop up by .093. The stock iron open chamber heads, IIRC have a depth of .080; so yur .013 too far out. Adding the minimum Q of .025, yu'll need a gasket of .013 + .025=.038 Doable but just barely.
However, again, where is the top ring? If the Top ring comes too close to the top of the bore, where all the heat is being made, the gap shrinks at the rate of 3 to 1 for every .001 bigger it gets. This could be an issue, in another way, namely; with the ring sawing back and forth in the groove as it heats and cools, guess what it's doing to the ring land, which is where the ring seals to the piston? yes, it is, wearing it out prematurely, and it is wearing out in the most important part of the stroke.
But if the ring gap shrinks to the point of butting the ends together, it's gonna either slow the piston to a stop or tear the ringland right off.
Furthermore; what is your compression ratio gonna be with that head chamber being nearly filled up? And
what gas will you then be forced to buy?
Or will you even be able to run on pump gas?
Whatever company offers a stroker kit, has thought this all thru, and the pistons in the kit are worth every penny you pay for them.
Having said all that, the KB107s that I installed into my 1971 360 block, with a stock 3.58 stroke crank, did come in at the design spec of .012 below deck; so I would have been able to run the .028 gasket for a Q of .040, on a closed chamber head. But I chose a different route.
And, IMHO,
on the street, the difference between a 365 and a 384 is as good as meaningless...... because; at the bottom, either will annihilate the tires, and your 60foots will measure in the 2.2 or more range, and yur gonna have to shift before you hit the speed limit of 65 mph, and when you do, your rpm will drop right off the cam. Whatever power makes a 384 cuber faster, on the cam, to 65mph, will be lost in the 60ft, so not a chance would I build a 384 over a 365 for street use, unless the kit was really really affordable. Instead, I would spend some extra money on the heads.
