1966 I-600 diesel starter question

Hello, I just had the starter re-built and the bendix is still not engaging. I got a couple batteries that still hold good voltage but are a little under in cranking amps. I’m really leaning towards that, but just curious if anyone knows what kinda cranking amps that stater is looking for? Can’t find it in the books.
Thanks

Amp draw can depend on load put on starter , hot -cold engine . Bench test or actual loaded in turning engine .
From about 300/400 to 800 amp draw . Then some large starters used on diesels can be in 1,000 + rate . 
As the starter depends on it spinning to move drive forward into ring gear , I would check spline on armature to be sure it is not bent ad drive moves easily on splines .
 Bench check to make sure when starter comes up to speed the drive advances on shaft and returns when power is cut . 
 Info below is from Yesterdays Tractor page .
Need the starter number to get the exact specs. Here are a couple examples.

Starter number 1107093, Spec number 2394
5.6 volts, 50 amps min, 70 amps max, 5500 rpm min.

Starter number 110096, spec number 3520
5.7 volts, 90 amps min, 125 amps max, 4500 rpm min, 6400 rpm max.