Seb says on 13/Sep/11
He is listed as at 5'6" on another site. Personally I always enjoy his performaces.

Mr.V says on 22/Feb/11
On this article two different questionaires compiled by Stockwell are put next to each other :

Click Here

The first one is from the 50's and he gives his height as 5'7 there . The second one is from the 70's ( when he had already become a star ) and by then he had apparently started to claim 5'10 .

5'7 must be it .

guyfrommars says on 26/Jan/11
He never looked taller than 5'7" next to 6' Scott Bakula in Quantum Leap. Closer to 5'6" barefoot.