The CST3026 IWIS chain is the very best quality and by far the strongest Simplex cam drive chain ever produced fort he A-series. I had my IWIS agent here in the UK have the chain especially made for me after becoming seriously disgusted with the ridiculously poor quality cheap chains then available from all the usual suspects.  

 

I had used the 'standard' IWIS simplex chain to good effect for most road-used applications, but I wanted a better component for use in race engines. The CST3026 'big pin' chain is the result, a chain originally developed for the Cosworth DFR F1 engine. This chain has proven so strong and such good quality I have been using it on my serious, out and out full race engines running 300 degree, rapid opening ramp, 0.350” lobe lift cams and 1.5 ratio rockers with 320 lb nominal rate valve springs. In a years racing the cam timing changed by a mere quarter of a degree. 

 

A common worry is 'are the standard sintered steel gears strong enough?'. Some had said they have had them break or seen others have them break. Sintered steel is extremely strong, though brittle. Any abuse can cause cracks in the material, particularly between the holes. This is generally caused either by folk whacking the gear with a hammer to get it on, or using levers to remove it.  

 

Unless the history of the cam gear in particular is specifically known, fit new gears. I have only ever used pre-run gears removed from standard engines.