I have a 109 block which been decked more than 0.010. Is there a supplier of a timing set shorter than 0.010" under the nominal crank center line to cam center line?
If a .010 under won't be tight enough, you may need to use a TA Performance billet gears and link type chain and use a tensioner. On a roller, if you have 1/4" - 1/2" play on the slack side, you will be OK.