You can use stock parts, except rods but sbc in an Olds to make a stroker. Because the Olds 350 has thick walls, can go over +.100" oversized, stock sbc 400 pistons or any of the oversizes will work. Now combine aftermarket 6" sbc 2" small journal rods, they never came that length stock. Or get a 6" with 1.88" Honda journal aftermarket rod. Olds made a factory forged steel crank from 64 to 67 in the 330 V8. I have 2, not super hard to find. All small block Olds have a 3.385" stroke, crank needs to be in good shape with standard journals. Now offset grind the 2.125" rod journals to 2" for a 3.5" stroke or the Honda 1.88" journal for a 3.6" stroke. With a 4.185" bore size and 3.6" stroke puts the Olds 350 around 390 ci. The 4.125" and 3.5" stroke, 375 ci. A 4.155" bore and a 3.5" stroke is 380 ci. That is how it was done for years in the Olds community. I have custom 4.390" Venolia pistons on Scat 6" sbc 2" journal sbc rods and a 330 offset ground crank for 424 ci from a 403 block. Technically one aftermarket part in an Olds 350 for a stroker. The same thing though, 50 extra ci with a smaller bore for better cooling and a stronger, lighter aftermarket 4" stroke crank is a no brainer in a performance application.
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