After all that^^^Get rid of the in-chamber heat and/or hot-spots.What gears is he running? What tire size?TC stall?Headers and duals?
Of course, I would set the T-port sync and slow that timing curve, and vacuum advance is a must in a heavier street vehicle. I would back up the timing to closer to 12*, if the T-port sync allows it, then I would put a 2-stage timing curve in it to get about 28* at 2800, then slow it down to in the range of 32 to 36 by much later, say 3600rpm.After the ping is gone in power mode, I would put the biggest V-can on there I could find. I would set it loose to bring in all the missing advance at part throttle, and tune that baby for driveability. .
Is there a chance you are forcing idle-timing on her?
You said you set it to 18 and it had 28 all-in; that's just 10 in the dizzy. This is not going to work,no-how.If he had it at 10*initial, it would have been 20*all-in; which would suck for power, and it shouldn't have pinged unless all-in was at 1500rpm or some other equally ridiculously early rpm. That dizzy is all wrong for this application.
I would suggest a regular LC teener type dizzy. Something with a Vcan, and at least 20*to 24* in the centrifugal. Most of those old girls already have the 2-stage curves in them.Just borrow one from a pre-leanburn car around 73 up.Drop it in , set the power timing to 34* at 4000rpm and roadtest it without the Can hooked up.
If that pick-up is stuck with 2.76s,32s,an1800TC,and a wiener single exhaust system,there may not be much you can do, but the slow curve is a step in the right direction.Trade that race-dizzy away ASAP.
