ok here the problem

We have a cast crank 440 (1977) but we are putting it in a 70 and are just running PS// we got a 4 groove crank pulley the one with the bigger to groves in the back with the smaller two in the front ,, we got a 1 groove water pump pulley 70 stile.. but doesnt fit hits the crank pulley...

What combo will work ?

is there a difference between a cast and steel crank pulley ?

see attached pic

The problem that you may find is that Ma Mopar had several possible combinations for pullies. There isn't any difference between the pullies for a cast crank versus a forged. The Cast balancer has a recess that allows the crank pulley to sit in. In other words, to my knowledge, the pulley will sit in the same position whether a cast crank and external balancer are used or a forged setup.
I have found with all of the different pullies, compromises can be made . It looked to me that your combo didn't fit because the water pump pulley was too large. The solution to that situation could be to use a smaller pulley on either the crank or water pump.
With A/C or not, P/S Federal, P/S Saginaw, smog pump or not, late 60s or mid 70s, there are numerous ways to put this together. I have been fortunate to live near 3 self serve wrecking yards to pick from.
What combo will work? I had to find a non A/C big block . I took the 2 groove crank pulley, the deeeep water pump pulley and all the brackets.

ok that helps ... I was told that a cast crank pulley was the only way .. as the offset on a steel crank pulley was deeper because the steel crank dampener was thinner...

So now ill look around for a late 60s crank pulley..

you would think someone by this time would have layed all the fitment info out..

ok i just read this can any one tell me if this is true

They sell a 2 groove crank pulley and list it to fit SB and BB ..

Now it that true ..

yes it is true

some crank pullys will work on sb and bb engines

I think the non a/c sb pully is the one used on a bb

they have a 2 groove non a/c pully for a sb and a single groove non a/c pully for a sb

IIRC either of those would be the one to go on a bb