how did Harley end up with 2 engines only being 1 cubic inch different?

95 & 96 cu in

 

95 was by bore. 96 was by stroke

88 with the big bore kit was a 95

88 with the longer stroke was the 96
That's why the big bore cylinders would make a 88 a 95 or a 96 a 103. The Pistons have different areas that the pins go through for the different strokes though. I hope I explained that well enough or accurately

 

so a big bore kit would make my 96 into a 103? would the lower end have to be opened up?

 

no just bore ur cylinder and new piston u get a 103

 

Just find a take-off set of cylinders and pistons on E-bay or in the Classified section here, have them cleaned up and swap them out on your motor.

 

I will keep that in mind, this Harley stuff is addictive and expensive. I have an rbracing 2 in 1 coming in today

 

You can even bore your stock cylinders to take your bike from 96" to 107"...

 

You sure can see my sig.