The cheaper sets chains will stretch so you need to install it straight up or 1 or 2 degrees retarded to start with. As the chains stretch the cam starts advancing, moves the intake lobe closer to TDC, I think As the chain gets longer between the two gears the cam sprocket moves towards the top of the motor, IE advancing You might want to rethink using that cheap timing sets,I put a Cloyes True roller timing set in my street low deck stroker motor that has a solid roller cam with 630+ lbs opened pressure, I shift it above 7000 RPM and it is a street/strip motor with over 3000 street miles on it also, same chain and gears for five years now I have had that motor apart several times since the first build, change cam timing, change cams, change the crank to a longer stroke, changed heads then and then to freshen the rings once to get rid of the low tension oil rings good parts are worth the money Trust me on that