Timing help

I run a small block with Mallory Sprint Mag.
In the past I set the initial timing by lining the timing mark on the crank with the 24deg timing mark on the eninge plate then drop the mag in with the rotter button pointing at the mark for number one spark plug. Usual this get me close normally just a slight adjustment once the motor is running.
I did the above but the timing light is saying that the timing is about 75deg advanced, now I know that cannot be right as the motor watnted run with that much timing.
Has one had the same problem and if so how do I fix it?
The only thing that has changed from the old combo is increase in stroke and comp.
Gone from 312ci to 355ci and 10.4:1 to 11:82.1comp.

 

What style of timing light are you using?
You may want to double check TDC using the positive stop method.

 

Timing

I use a Proform light has been fine in the past.
I have check everything at least four times e.g. timing mark hasn't moved, mag hasn't moved.
Still has the same problem.
When I tryed to chenged the timing with the motor running back to where the light says 24deg is, the motor sounded like it was firing on the exshaust stroke, got very fumey and wouldn't run under 2000rpm.

 

Try setting the timing with the # 6 cyl, may be the crank you put in is broke in the middel, the timing mark will be the same on the degree weel at # 1 t/d /c and # 6 cyl t/d/c

 

Wouldn't the motor sound off if the crank was broken?
The motor sound fine when running and I have turned the motor over with no plugs in and the pistons are still going up and down in all cyclinders.
Motor isn't a Chev, Ford or Crysler.
I'm in Australia it a Holden which is a GM brand motor is similar to Chev but leading cyclinder is on the right side of the car and different firing order.