I am in the process of getting close to finishing my small block stroker race engine and have a couple of options as far as the stroke I will use and wanted to hear opinions on here as to which way you guys would go and why one is better than the other.
What I have is a set of JE dome pistons made for the Indy cnc 245 cc Indy heads I have that Ryan J setup for me they are 4.06 bore 1.200 comp height. I have to different sets of rods I could use both are small journal chevy size one set is 6.2 the other is 6.3 in length both are steel rods.
This will be used in Speedomotive Uber 318 block if you are not fimilar with their Uber block they sleeve all 8 cylinders mine is suppose to be good up to a 4.115 bore size but I will be using the above 4.06 pistons the block has already had the lifter bores bushed its been line bored and decked to run Cometic gaskets with a deck height of 9.554 it has the Milodon splayed caps not looking to hear about they wont work I will run it till it blows if thats first pass or if it runs forever.
Here are the choices for crank 4.125 with the 6.3 rod which will be a 427 it will also have more compression it would actually push the piston above the deck 8 1/2 thousands.
Or 4.25 crank with the 6.2 rod which will be a 440 it will have less compression the piston would sit 29 thousands below the deck.
Which way is best and why? The piston being above deck 8 1/2 thousands is that going to be a problem on the one setup or will a thicker head gasket be the fix?
This will be run in a tube chassis D100 dodge pickup fiberglass front end with a powerglide and 5.38 gear 16x33 slick mostly 1/8 mile racing.
Maybe Ryan J could chime in, he don't know it yet but he is going to assemble it and dyno it for me in the near future also he ported a W2 Holley Pro Dominator tunnelram for me to match the Indy heads. I have a set of C&S Aerosol 1050's I want to try with the tunnelram against a Indy single four with a 1050 Holley on it. Thanks for your opinions.

How are you coming up with .0375 difference when there should be only .025?

4.250
-4.125
=.125
-.100 rod difference
=.025

The 4.125 crank would be using the 6.3 rod the 4.25 crank would be using a 6.2 rod two different strokes using two different length rods.

You would figure the stroke for the 4.125 crank at 2.0625 and the stroke for the 4.250 at 2.125. So 2.0625 plus 6.2 plus 1.2 piston equals 9.562.5.
Or 2.125 plus 6.3 plus 1.2 piston equals 9.525 hope this helps.

Assuming that you are running a flat top piston I would think that the 427 combo would be the one to run. At 8.5 above the deck it would be easier to run higher compression and proper quench. Setting quench at .0035 to .0050 would be much easier by playing with more available head gasket thicknesses than a piston .0029 in the hole. I am no cylinder head expert but I have heard that a piston below deck usually hurts flow with a good flowing set of heads like your Indys.-Randy

Sorry, just reread your original post and noticed you are running a dome piston. If there is a small quench pad on that piston I still think the 427 combo would be a better race setup.-Randy

my indy 245 made 720ish hp w a 950 carb,and 1 gal of racegas mixed 3 gal's of 92, its 440ci just sayin.

I'd run the 440 BUT I would have the block milled to
give you 0 deck... your running a glide and 1/8 mile
so you want a LOT of torque

I agree with Mr P Body on needing alot of torque with the glide and running 1/8 mile mostly but I don't know if I can mill that 318 deck down to 9.525 without it getting kinda thin from what I have been told the 318 blocks start at 9.578 so it would be taking 53 thousands off versus stock or 29 more than it is now.
I also like Randy's idea on the 427 because if I leave the deck like it is now it will have more compression also will have a rod ratio just below 1.53 the 440 would have a rod ratio just below 1.46 so the smaller engine would have more compression and better rod ratio unless I deck it more as Mr P Body suggested.

If you are worried about torque with the 427 combo, have RyanJ put the larger 2.15 intake valve in those heads. Use a cam with less duration say 260-270 and more lift. The larger valve will keep flow up,the short duration cam with less overlap will increase cylinder pressure and low end torque. I have seen this work firsthand with the Indy heads. Ryan does this mod on a lot of Indys.-Randy

Yes it is a stock block I think they have on their website that they can get sleeves that can go as much as a 4.220 bore. I hope it will last it has alot of nice machine work done already I guess I will be the first person to try one in a true race setup I was having trouble finding a R block when I found this one for sell a couple years ago so I bought it.
It also has a half fill of hard block done by them. I am planning on carrying it to Ryan J in the next month or so I know this is the busy time of the year for him so sometime after the first of the year we'll see if it makes it past the dyno or not.
He ported a W2 Pro Dominator tunnelram for me to match the Indy heads. I have a Dominator top for it that I want him to try two C&S Aerosol 1050 Dominators I have against a single plane Indy intake with a Holley 1050 dominator.
If it survives all that on the dyno maybe it will last a little while should be interesting to see.

What bore size does the Darton sleeve start at?

I'm not sure but my understanding is they completely gut the block and install the Darton sleeves. I think I was wrong about them having some that can be bored to 4.220 but they must have some that can go 4.200 according to their website you can build a 471 so I guess that would be a 4.200 bore with a 4.250 crank.