W2 Heads on 1996 Magnum 360 Block

Got the engine torn down. Crank looks good, going to use stock rods with ARP bolts. need to pick a flat top piston. I will have to stay with the 904 Automatic for a while. I would love to go 4spd ASAP, but it realistically is very far away. Do I use this flex plate for Magnum 360 to 904?
https://www.summitracing.com/parts/bmm-10239/overview/make/dodge.
Asking because I am trying to get the block and rotating assembly to the machine shop by Friday and would like to go ahead and order parts.