Ok Guys. Big debate here at the shop. Quick run down. 489 BBC. Crane Cam #138601, Billet Steel Mechanical Roller. MSD Pro Billet Distributor #85551. One engine builder says use an Melonized Iron Distributor Gear. Another one says no, must use a bronze distributor gear. So help us decide once and for all. Which one is CORRECT? Thanks ahead of time.

Don't need a poll, if you have a cast iron gear pressed onto your billet core then you use a melonized gear. If you don't have a pressed on cast gear and just the billter steel gear, you use a bronze. Your cam card will say if it has a cast gear. I just went through this in my 489. Mine does have a pressed on cast gear and my engine builder used a bronze gear accidentally and it failed at 1600 miles. I now have the correct melonized cast gear.

Cast gear pressed on my billet core...

http://www.statesv8sracing.co.uk/10.html This guy is running your exact cam and it has a pressed on cast gear. You need to verify however. I'll wait to vote.

Not ALL cam cores are available with a pressed on iron gear, at least not when I bought mine. Mine is a steel billet Comp custom grind on a reduced base circle - press on gear wasn't available. I had three choices for a dist gear - Melonized, bronze, or polymer. I chose polymer from Comp Cams - about $110. Three years and several thou street miles absolutely no problems. http://www.compcams.com/technical/Catalogs/106-07/235.pdf

From the Crane catalog notes for this particular camshaft:
"camshaft incorporates an integral cast iron distibutor gear. Aluminum bronze distributor gear not required."

I am sure that this is on thier web site too, which is still up as far as I know.

There is your answer.

Thanks guys. No, that info is NOT currently on their website. Secondly, the gentleman has found his cam card and it states it has a cast iron distributor drive gear. The issue is now resolved. Thanks for all the quick responses.

When I was researching this, I called both Comp Cams and MSD and lucky got the same answer Melonized, which is what I had on it.

I'd call and make sure.

Comp cams composite gear ...:thumbsup:

No reason to run a composite gear on a cast camshaft gear. The composite gear is for more longevity on steel rollers without the pressed on cast gear. From all my research the GM melonized cast gear is bullet proof on a cast camshaft gear. :thumbsup: