take a compression test on 2 cylinders.
for timing at any rpm you basically increase it until the rpms no longer increase much as you turn the distributor then try it there but you may need to back it off around 2 degrees.
you "can" run a lot of advance in a low compression engine but that...
CAM
this cam rumblefish suggested with 1.6 rocker arms.
Voodoo Hydraulic Flat Tappet Cam - Chrysler 273-360 268/276 - Lunati Power
VALVES
Have your stock intake valves back cut.
COMPRESSION
unless you milled the bejesus out of your heads and zero decked your block, you have around 9.0...
you can also use the eddy high port heads and have them ported and use a light weight valve train with ferrea hollow stem valves and possibly manly nextek springs
steel main caps with dowels
ati dual inertia ring crank damper
if the block is oily get some pure white tide . put 1 cup per 3 gallons of water in a tub from home depot and soak it for a day.
rinse well
buy oxalic acid crystals online . mix them 1lb to 1 gallon of water .
fill the tub and soak the block for 3 days.
do not breathe the fumes ad do it in...
if your heads are closed chamber and your pistons are flat top, you want between .043" and .034" of squish/quench clearance.
run the 3.55 gears as suggested and 10.0 compression.
if you run vacuum secondaries, tune the secondaries with different springs until it runs best.
set your timing...