I just purchased an XFI roller cam from comp cams and was wondering if I have to change out the distributor gear or not. The distributor gear in the car right now was from a motor not originally equipped with a roller cam. Comp recommends their composite gear, but im not sure if it is absolutly necessesary to change it out or not. Anybody know?

 

its always best to start out with two fresh metallic surfaces. just as you should with the cam and lifters. its not a requirement. if you have two smooth surfaces that constantly rub each other, the amount of wear would be normal. however, if you have one worn surface and one not. the damage from the worn surface can limit the integrity of the new surface and cause premature wear or even failure before it should.

this isnt to say that the gear you have on their now will produce any premature wear or any wear at all. but two fresh mating surfaces is always good. and i wouldnt get the most expensive gear i can find. but just a new one will do.

hope this helps.

 

I've been running my '86 distributor with stock gear on a ZZ4 cam since 2005. No issues.

 

the distributer gear should be the same whether it was a roller cam or flat tappet.

is the distributer a factory HEI? in my experience it is hard to get a hold of just the distributer gear unless you order from a chevy dealership and wait well over a weak. a lot of aftermarket gears are .500" or .491" shaft diameter. i messured the factory shaft and i think it was somewhere around .450". I ended up going to the junk yard and pulling dizzys untill i found one with an excellent condition gear.

 

The distributor is a factory coil in cap HEI unit. It came from a car with a flat tappet cam though and I was always told that the gears on those distributors are different. So should I switch out to the composite one that comp cams recommends? How well would that type of gear hold up/wear over time?

 

Also what size gear would I need? .500 or .491?

 

.491"

 

The distributor gear is the same size for both roller and non roller applications, just the material of the gear should be different, correct?