Admittedly the investment for a set of stroker flywheels is pretty hefty and you wouldn't crown this wonderful device with a set of inferior pistons, would you? The Wrecking Crew, for one, didn't want to gamble and had these special pistons made by the renowend German manufacturer Graf. Those guys supply the vintage and classic racing scene since decades and you can simply trust their material. And yes, they are more expensive than your average 45 piston but a seized or broken piston at full throttle is by far more costly, guaranteed.
These special Graf pistons are made for small twin Flatheads with 4.5” stroker flywheels. They are shorter than stock pistons so the engine case baffle plates do not need to be removed. Complete with piston rings, pins and locks.

Forged big bore pistons by S&S for 4-1/4" and 4-1/2” stroke flywheels (88 cui./93 cui.) with stock 8-1/2" diameter. Sold as complete kits with front and rear piston, rings, bolts and clips.

Forged 3-5/8" bore stroker pistons. Applications for this piston include 88" (4-1/4" stroke). 93" (4-1/2" stroke), and 96" (4-5/8" stroke) engines with stock 8-1/2" diameter flywheels, and 98" (4-3/4" stroke) and 103" (5" stroke) engines with 8-1/4" small diameter flywheels. Sold as complete kits with front and rear piston, rings, bolts and clips. Made by Wiseco.

An easy and economic way to increase displacement of 883 and 1100 Evo Sportster models to 1200cc. This kit with 3-1/2” bore forged pistons only requires to bore the stock cylinders from 3 inch to 3-1/2 bore, or purchase new 3-1/2 inch bore cylinders. No combustion chamber modifications or flywheel rebalancing is necessary. Compression ratio will be a very streetable 9.5:1. The piston skirts are coated for reduced friction during break-in.

Used for boring 883 Sportsters to 1200, these KB High Performance pistons are made from Hypereutectic 390 alloy. This low expansion alloy allows for a tighter piston to wall running clearance compared to forged pistons. The pistons feature fully machined crowns and valve reliefs. The wrist pins are full floating. KB pistons are sold as pairs and include piston rings and triple wound spiral locks.

These KB Performance pistons for Harley-Davidson motorcycles are forged from low expansion 4032 alloy. They are preferred for high performance / high compression applications. KB pistons are sold as pairs and include piston rings and triple wound spiral locks.