Most of you LT1'ers that have opted for a Billet cam had to take into consideration whether to use the Bronze gear (Now discontinued by Crane anyway since Crane is gone) or suffer excessive wear on the gear that is driven by the cam and turns the oil pump. I'd rather refer to it as the oil pump drive gear than the distributor gear but that's what the books call it.

Another source of gear excessive wear is opting for the HV Melling oil pumps. These pumps put a lot more load on the drive gear so they wear out frighteningly more quickly. I'd lost one otherwise perfect 355 motor because of this. I was in a 20mph school zone, driving my daughter to school when I heard a high pitched squeal. My daughter and I shot each other looks like, "wth was that?!", then I looked at my gauges. Whoops! Zero Oil pressure! I shut it off and pushed it out of the way. Peeling the motor apart found all teeth of the drive gear were gone. With the replacement 383 solid roller, I put in a bronze gear. Having to peel that motor apart 7 months later, that bronze gear was about a month away from also being toothless. Inquiries to various lists/BB revealed that most guys said, (a) don't use a HV pump and (b) use the polymer style drive gear.
I found the poly gear at Jegs but it is a .500 shaft size. The LT1 requires a .427 shaft. So, just like the guys said, "find a machinist to drill a bushing for it and make it a .427 shaft hole.

After ordering and dropping off at my machinists, viola! Here it is...






Don't know if you can see it but look how sharp the tooth edges of the Bronze gear are that I took out are compared to the composite.

 

looking at the picture the composite gear looks to have a bigger outside diameter than the bronze gear. tough to tell on a computer though.

 

I just held them, end to end, and they look the same.

But... since this is the first occasion for me to use my new digital Caliper , I went into my tool chest, brought it out and measured each several times.
Bronze Outside Diameter(lower portion).....: .0881
Composite Outside Diameter(Lower portion : .0883
Bronze Outside Diameter(Tooth portion).....: 1.224
Composite Outside Diameter(Tooth portion : 1.237

You have a very discerning eye my friend
Thanks,
Dave

 

So will the composite gear still work since it's alittle bigger?

 

looks like the bronze gear might have been small to begin with, that could've caused the premature wear for certain..

 

I'm going to do the same thing as you did. I lost oil pressure last Saturday and I had a feeling it was the oil pump drive. So I pulled it out and the gear was missing teeth and it looked horrible.

 

I have installed several AI billet cams in my own car and friends cars and we don't have any trouble. Buy the right parts the first time, problem never exist then.