Most good rebuild shops can sell you a heavy duty GM starter for a reasonable price. What you get at Auto Zone or other parts stores are the generic light duty type. I'm not impressed with the small aftermarket ones that Summit and others sell. They are way pricy and I have seen some installed with numerous shims in order to fit. The stock flywheel will have 168 teeth.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine