i set gears at dot to dot, then crank engine over till #1 intake is closing then with cut down clothes hanger or other simple rod hold against piston as someone turns crank with wrench till piston comes all the way up(slows down as it hits tdc.
Also one handed use a starter button and crank till compression pushes finger off plug hole and then creep up. The timing mark should be at/near tdc.
Most big blocks I have tuned under 11-1 we have good gas and I generally set 14deg up to edge of timing tabe which if right is usually about 18deg. On HEI I make sure to piggy back new 12 guage wire from firewall connector to HEI plug. I just remove bulkhead connector, remove wire from connector. If I have spare 52 series connectors I will simply remove braided covered resistor wire and install new IGN wire, If customer doesnt want that terminal removed and folded back I also open strain relief tabs, with cleaned terminal and some liquid flux Ill lay my 12 ga wire under strain reliefs and solder it on top of the crimps. Push that black gooey crap back around and tape wire to the harness or few small zip ties depending on length of time it may stay HEI.
New HEI plugs are available everywhere.
I always crimp as solder electrical stuff.
On street engines with moderate cams STOCK HEI weights with lightest springs in Accel kit or MSD kit works well. Make sure the centrifugal stop bushing is present on bottom stop pin of distributor. 14-18 initial and the light spring generally give best road performance w/limited track. Listen for spark knock, starter buck.
After setting timing and adjusting carbs idle mixture and speed, THEN hook vacuum advance up to manifold vacuum. and readjust final carb adjustments.
This generally gives you proper off dyno starting place. If you get spark knock, hard surging or starter buck pull 2 deg initial. If you total goes past 55-58 you have distributor stop bushing issues or long travel vac advance. or possibly the vacuum advance can is adjustable for maxlength through vac hose port.
Again I like 53-58 MAX advance at 2500-3000 vac advance hooked to manifold vacuum(revs up engine and timing goes up) What vacuum advance is for is mileage. and you want it to DROP when you open throttle.
In car way to dial in initial and centrifugal is start at 14 and advance 2 degrees till it bucks starter hot, back off 4 deg. This is base and can be tweaked as needed.
Centrifugal advance needs to be in BY CRUISE RPM IE 55mph=2800 or just below. or what ever your final gear gives you at 55mph.
Then adjusting mechanical/centrifugal max with stop bushing. and mixing and matching springs, I sart tose with both lightest then swap in on light one medium, then two medium etc. BUT best seat of pants/track time dial is a working from their.
Adjusting max mech advance and initial for best 60 ft/ET. Street cars can keep vac advance line on as open throttle negates it if vac adv spring is good.
Some cars with lumpy cam racing needs vac line removed and plugged.