Originally Posted by tony xa
Most 3.850 cranks are set up for 6.125 rods and there are pistons avail that are designed to be used with the 3.850 crank using 6.125 chev rods so the pins shouldn't intersect the ring grooves.
The above is not from a expert so don't treat as 100% correct
I did notice that most americains run 6 inch rods on their 393s
I just think if the cranks are advertising 6.125 then it should be easier and correct also easier to get the correct pistons to.
My 393 has 6" rods and the pins intersect the oil ring.
...I can't imagine a 6-1/8th" rod not moving the pin higher up in a 9.2 deck. My deck clearance was .008".
This is about the easiest thing to sort out...just measure your deck and do the math...gents! Let's say that your block measures to: 9.204" before machining. Figure that you're going to clean it up .004"-.006"
9.200 (possibly 9.198)
1.925 (2.00 for a 4" stroker)
1.150" - 1.148"
You don't want to be under 1" for the pin height. Also, if you're intending to run reverse dome pistons, you're probably better off going with a 6" rod to gain a bit more room under the dome.
Also, no problem spelling Americans as americains. I've seen far too many americains spell Australian as austrailian. It must be why so many Aussies call us Yanks?