I have written this up several times in the past on here. As others have also.
1. The SBC should have side mounts.
2. Use a universal tubular cross member. They fit "original" side motor mounts.
3. You can use the same style cross member for the trans if you don't have anything.
4. Mock it all up to determine which cross member shape works. Purchase where returns are free, then mock up again to get all the clearances figured out.
5. The usual issues are firewall clearance/dizzy clearance, exhaust, steering, linkages, drive shaft length/angle, Rad and fan.....
6. Set carb mounting surface level.
7. Sit and stare and think and measure.
Mock up motor and trans with cherry picker slinging, jack stands, blocking, chains....whatever, to determine location of cross members and all other issues. This will not be a difficult swap. You didn't say which SBC or it's year.... and didn't say how you want to shift the 200r4.
Example only
