Hi grizzly,
The answer to your question is a definate "Yes !!!"
I am building a 457 cu in out of a 72' 340 motor.
It has been sleeved by Divorak ( think he is still in business in Waldo, Florida)
I will include a few pictures to show where i am at.
It is an Old project for me that I have still not finished as I have been running a big block 540 stroker and 8-71 BDS in a pro street/drag race dodge demon 340.
the 340 is out of this same car, but is not numbers matching to the car.
We figure it out like this...
4.200 bore size x 4.125 stroke crank or as the formula goes...
4.200 X 4.200 X 4.125 X 8 X .7854 = 457.19
I was told that I could go even bigger, but wanted to try this combo out first.
It has probe pistons that stick up .033 out of the hole.
W2 heads with 2.08 intakes and 5 angle valve job (30,35,45,60,70 )
Mopar Performance valves that are back cut/front cut w/ .372 stem.
Solid roller cam 622/624 and also split duration 258/264*
Heads where done by Dynamic racing engines in Tampa, Job # 253 & #254 ( not sure if he is still in business either?)
We have a holley strip dominator w2 intake with a adapter plate and a single 1050 dominator at this time.
Combustion chambers are 66 cc with the w2 heads and a fel pro .045 compostion head gasket.
Valve to piston clearence is .115 intake and only .028 exhaust ( so we need to flycut the exhaust side of the piston's a bit!)
Piston to head clearance is .135
rockers and cam are crane roller.
I have since bought a cat gear drive for it and need to do the machine work to install it ( drill and tap a hole in front of block)
Our block has been filled up to the freeze plugs with hard blok (had to make it/mix runny just to fill it and wait a long time for it to dry!!!)
Pistons have the ring lands moved down a bit for use with nitrous fogger set up.(just in case)
If we figure it right our pistons leave us at 12.2 to 1 compression ratio.
They are available in any combo such as a lower 9.to 1 ratio if we wanted to change ( we like to race!)
I would not be discouraged in the least bit to do it again with a block that had a cracked bore as was our case.
Not sure what kind of power it will make yet.
I dont dissagree with starting with the R3 block if you have the means, We did it with this one just to find out what we could build to be different.
Hope the pictures come thru!
Grant Eaton
386-561-1181.