6BTM or locked out timing?

Hello,
I am still collecting parts for my 225 turbo build.
Now i am at a point of wanting to select my ignition control.
I currently run a stock distributor (1972)with pertronix module.
Will a 6BTSM work with the stock distributor? I have an available dizzy from a later slant, 1978 i believe or can i just lock out the distributor to 18 degrees? How is the distributor locked out, i havent seen a procedure as to how to do this but am still searching. Car will be street driven always with some highway use.
Money is of concern, but i will spend it where it makes good sense. Thanks

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