i have a 89 350 motor i bought from a friend and i tore it out of the truck and broke it down. looks to be rebuilt with new rods crank and pistons with a bore job.

i want to know if a 350 is still considered a 350 if there was a 305 crank installed?
my crank reads 14088526 and its a 305 crank but put in a 350.

is this 305 crank  lowering my hp or performance in any way?  

14088526...305,350...cast....medium journal...3.48" stroke

this crank was used in both motors. i know that the 305 cranks have different counterweights to compensate for piston weight. cant tell if it is a true 350 crank, or a 305 without looking at it. shouldnt hurt performance if your machinest does a good balance job. if your buying new parts, and want to be exactly sure (for some supersticious reason...) but a eagle or scat cast replacement for 250$.  

whats the stroke of a 350 crank vs. this 305 crank with a stroke of 3.48?

this is a 350 motor but wanted to know if there is any differance if a 350 or a 305 crank was used in a 350 block.  

The 305 and 350 both used a 3.48" stroke. The rod and main journals are also the same diameter on both cranks. In the majority of the cases the cranks were even made of the same material! (nodular iron of course)...

The differences start in the factory balance as the piston weight in the 305 is less and it's because of this reason they cannot be interchanged without re-balancing.

The way to identify the 305 crank is outlined in John Lingenfelter's book, "John Lingenfelter on Modifying Small-Block Chevy Engines." The process involves laying a straightedge along the crank's "machined surfaces" while the crank is laying flat. Five points are included and only the 305 crank will allow the straightedge to lay flat across all five points.