Cam advice for more torque from 340

But worth a whole lot more than +4% for low RPM torque.

9.5-9.6 looks right for SCR, assming the heads have been milled about .010" before. The XE262 installed straight up as ground, which includes 4 degrees ground in advance, will give DCR of 7.9. That is pretty good territory.

The XE268 installed at an added 3 degrees of advance (3* installed + 4* ground in) will give the same DCR, a bit less low end torque but probably pretty darned good, and will be a bit better up top even with the added cam advance.

Running a heavier car might nudge me towards the 268.... it would help keep away a bit more from detonation if the timing got a little off or the fuel bad; heavy loads can put the engine a bit longer in 'danger' territory. And if you are cautious with the ignition timing in 'sneaking up' to the 30 or 30+ degree total range, then you'll be fine with either.