I am building an engine from a 80'2 302 block and a 66 289 and i am trying to put on the timing chain cover but the eccentric is too thick for it to go on. the timing chain and sprokets are for the 302 but the eccentric is off the 289 as well as the cover. what is the easiest way to fix this, is there a different eccentic i need to buy or is the cover different? Thanks for any input

 

I put a 302 motor in my car, and I used the timing chain cover from a 66 car. No problems matching up. Is the cam new or out of the oringinal engine block? If it's new, is it seated correctly? I remember having to kind of press down on the front of my cam to lift it up a tad to make it fit into the last bearing socket. This may or may not be your problem, but I suspect that the cam might not be seated correctly or doesn't fit correctly...

There isn't much in the way of differences with eccentrics to my knowledge... I could be wrong. Hope that helps. Good Luck with it.

 

I believe your timing chain sprocket is too thick. Guess how I found this out. The 289 timing chains, even the double roller chains, use the narrower sprockets to clear the cover. The tolerances are already pretty tight, so a little extra thickness will cause the problem you describe. As always, make sure you have the cam seated correctly as that is an easy fix.
What you need is either a timing chain set that is specific for the early years (pre-1970) or get a two piece eccentric like the 1970 and later small blocks have. I used an edelbrock double roller in mine, but you can find them from other suppliers as well. Good luck.
Daniel

 

Yeah i just used a new timing chain set for the 289 cause the new one for the 302 was too thick, fits nicely now. thanks guys