A new balancer with timing marks is a tremendous investment for tuning, even a cheaper one at $125 for the street is fine. Itll help dampen much better over the stock stuff too.
Your graph looks like you have 24 degrees of timing on start up, then it shoots to zero degrees from 1500-2500 rpm and maintains zero degrees timing? Maybe im seeing that wrong?
Are you racing the car? If not my advice (which i dont mean to sound shitty) is sell off all that fancy mess and get a decent rebuilt or new HEI, throw some Mr Gasket gold springs in it to have all your timing in by 2800, 36 total and 14-16 initial. Accel sells an adjustable vacuum advance can for HEIs that is truely adjustable. I have mine only kicking in an additional 10 degrees for cruising cause thats what it liked most on 93 pump gas. Plugs look great, car runs great, with my 468 / 5 speed i get 16 mpg highway and awesome throttle response in the low end from the vaccuum can.
My brother had a locked out billet msd dizzy in his SB406 in a '71 nova that was in the 10s. Starter saver to get it running then it was 40 degrees locked cause it seen nothing but 3500rpm on the transbrake and 7000rpm all the way down the track. Great for racing but if you enjoy the street this is NOT the way to go.
An HEI and a 6AL box at most is all youll need for street car fun in my opinion. Lots of simple, cheap parts available for adjustments and tuning. On the other hand timing programming does sound kinda fun once you get it dialed in!
Does this sound right? It starts SO hard now when both cold & hot, it doesn’t want to turn over easily and takes a few tries to start. New battery + high torque starter so I don’t think either of those is the issue. Is this a common problem when locking a distributor?
Its starting hard cause you were rolling it over with 24 degrees timing is my guess.