I just finished buliding up a 1984 350 (hydraulic flat tappet) to go in my 88 IROC (originally a roller). I bought a Comp 262 cam for it and the fellow at Comp said to make sure the distributor gear wasn't hardened steel. I talked to a very good machinist who said if the dist. gear was a dark gray, then it was cast (good) but if it was shiny then it was steel (bad). It looks cast to me but.....so my question (finally) is this ...does anyone know what material the dist. gear on an 88 IROC TPI 305 came with? Where could I look this up? I called a GM dealer and got a big ' I dunno'

 

Cast metals can be hardened. Usually roller cams(which you originally had) are made from harder metal and use a harder dist. gear. My bet would be you have a hardened gear. It shouldnt cost to much to order a bronze one from summit.

 

It's bloody infuriating trying to get a straight answer from anyone - 2 people at Comp cams 'Cam Help' line gave me 2 completely different answers - one said I would be fine for sure and the other said I would have trouble for sure - the other problem is that the distributor from 1988 had a unique diameter (.427") that just about no other years did, thus making aftermarket gears almost impossible to find....sigh...

 

You should be fine. As long as its not a race roller you should be ok. Only race cams like the solid rollers utilize the hardened material that calls for the bronze distributor gear. I have never seen a hydraulic roller camshaft, stock or aftermarket, that requires the use of a bronze distributor gear.

 

Steckman - Actually it's a flat tappet that's in there now, it was a roller in there originally, and that's the problem - the original distributor might have had a hardened gear to go with that roller ....no one seems to know....

 

oooOOOooohhh. Do you know what TYPE of roller? Hydraulic? Solid? Like i said, i am yet to see a hydraulic roller that rerquires a bronze distributor gear.

 

It was a hydraulic roller. The new one is a hydraulic flat tappet with a cast dist. gear. But the original dist. gear definitely wasn't bronze. Like I said it looks cast, but apparently even a cast gear might be hardened.