rod lengths

i just changed my crankshaft from 4.375 to 4.250 x4.375 bore
i poored my chambers and get 121 cc with 7.276 rod and .070 gasket
i figured it is 9.65:1 cr
each .010 is .24cr
so if i want 10.9:1
i need .050 more rod length
5x.24cr= 1.2 cr +9.65=10.85:1
.050+7.276=7.326 rod length

this seems long compared to my other engines but they have different
piston pin height
does any one have a similar bore/stroke and what is your rod length and
compression

this is a .100 tall brad 5 heads bae4 tafc4.375 je piston
i just need to know before ordering rods if this sounds right
thanks

 

Rod length

I run a 7.306 rod with a 050 gasket in the same combo if that helps. That wasn't the crank on E Bay last week was it ?

 

thanks thats what i needed
does your combo have about 10.9:1 compression
no the crank was for my spare motor
thanks again