RE: 350 starter pinion to flywheel clearance
Obviously this engine has had a starter on it before. The 168 tooth flywheel is standard fare for 350's. An offset starter bolt pattern is made for 168 tooth flywheels. try and stay away from rebuilt stsrters and reconditioned flywheels. You should use new parts. If You have the right parts, They'll fit. You might have to shim the starter a bit, most come with them, and use a paperclip straightened out to gauge the fot. It needs to fit between the engaging tooth of the starter and the base of the meshing teeth of the flywheel. Pioneer sells new flywheels and Delco Remy sells new starters.