problems starting (kickback)

my truck has not been starting like i would like it to . sometimes it starts just fine other times i get a "grinding noise" along with a little kickback.
runnin 446 BB 12.5 CR, locked dist with 20* retard box, powermaster starter, optima yellow top batt, and alternator. with truck running and all accessories (msd, water pump, 2 fans) on i have 12.5-13.5 volts, but last night we threw the alt belt and dropped to 11 volts at idle running only water pump and ignition. i guess i figured the optima would do better than that.
so we were thinking of trying a couple of things
1-shim starter out so it disengages faster
2-add another battery
i just cant help but think that this thing should quit kicking back during cranking. thanx

There should be no reason to shim a Mopar starter. That's why they don't make shims for them.

too much cranking compression at startup, probably....back timing off a little more and see if that does it.

My 440 with 12.5 turns like a /6 with the mini.Timing is 15 base.Mopar starters dont shim.Like said they dont make shims for them.Either your starter is bad or timming is off.Did you find TDC to make sure its only at 20?Dont trust the balancer marks.Rocky

Start retards; 90% of the starts they make cranking easier. 10% of the starts they make it much worse.

It's much safer to start with the timing already retarded and then advance it with rpm (using weights and springs or using an electronic advance distributor or box).

Yup if you have a Pro billet distributor they will
1. cross fire with a start retard at any more than 10 deg retard. (I guess not as bad on huge GM hel distributors??)
2. if it starts and stalls you have to turn key all the way off or it's still in no retard mode.
3. go back to light springs and be happy "I DID" .
I use light mopar springs on an MSD pro billet as MSD chev springs are too stiff. I just want the mechanical advance to start and full advance after.

The problem is the MSD (if that's what you have). Spin the motor first, then flip the switch. This is the only cure. If you don't have a toggle switch, install one.
DC

starter is mopar perf..locked. didnt know about the switch having to be off to reset the start retard...makes alot of sense now. cant really run with dist unlocked need full advance at idle to pull vac for my class. had tried spinning the motor and then throwing the ign switch with some stock type starters but was breaking the drive gears. didnt have the balls to try it with the $250 starter. talked to powermaster today and got some good insight also (mostly that it wasnt going to start well with that much timing/comp). think i have some new things to try thanx to all.

The ultimate solution to locked distributors, crank triggers, etc (when using an advance curve is not viable) is to use an additional pickup in the distributor. Install the second pickup so that it will retard the timing about 20 degrees compared to the crank trigger pickup (or primary pickup in the distributor). Start the engine on the pickup that is retarded 20 degrees and then once the engine is running, use a dash mounted switch to switch over to the primary pickup. This eliminates advance curves and start retards but still allows full advance at idle speeds without risking kickback.