timing issue

[julescamacho]

i have a 67 340 and i cant seem to get it into time
its supposed to 2.5 btc but it wont run except when its at like 10+ btc
my question is this:
can the timing change over the years?

[gsjohnny]

the timing chain will definately stretch. does the timing mark bounce around when you rev it up and let come back to idle?

[julescamacho]

yep it does

[julescamacho]

yep it does

[julescamacho]

my camshaft is a little worn could this have anything to do with it?

[gsjohnny]

worn c/shaft, no. culmination of other parts, yes.

[71stage1conv]

Now might be the time to do some performance upgrading.:BROW:

[gsjohnny]

Now might be the time to do some performance upgrading.:BROW:

and what would you suggest.....:LAUGH:

[Carl Rychlik]

I think it needs a rebuild. How many miles does it have on it?