need a little help. ive had a weird concern for a bit only have 22 miles on the engine end everything is new including all of the wiring. when i had my wife cranking the engine i wasa under the car and observed the starter pinion gear comes out meshs with the flex plate and starts cranking and about a second later the pinion just fully kicks out and then trys to reengauge the flex plate teeth while its sttill turning and this time hits them and kicks back and did this 3 more times when i told her to stop.its a summit brand gear reduction starter because i have a billet fab oil pan with a kick out on the pass side the starter is positioned correctly the clearance when the pinion is at rest ( retracted back into the starter) is 2.54mm and when the pinion is held out with a scwerdriver using a wire feeler gauge the clearence between the point on the fly wheel teeth and the v or valley inbetween the starter pinion teeth is 1.02mm the summmit specs are 2.54mm and 1.0mm so that check out ok and my 12v reference from the ingition switch when held in the cranking position is 12.5 volts. so im kind of at a loss for what to check next the car has a 383 lt1 and a holly hp EFI system in it battery moved to the trunk starter relays and wiring battery and cables are new with in a few months old. any help would be nice i dont want to get to the point to where it rips or breaks teeth on my flex plate or starter ect... oh yea it has a pioneer sfi approved flex plate callies forged bottom end

 

Since you moved the battery to the trunk, I kind of suspect voltage drop at the starter. You need to check the voltage on the starter while cranking if possible. If it is lower than 8V or so, then you probably got a problem holding the solenoid in. Make sure you have a GOOD ground path and run a separate cable back up front if you don't. If all your connections are good and you have unacceptable voltage drops, use larger gauge cable. Seems like basic stuff, but that's where I'd go first if I had to troubleshoot it.