Depending on application, you might have to change oil pan and accessories/drive. The distributor needs to be an 85 style for carb or aftermarket with a steel drive gear.
If your wondering about items not working with from a flat tappet block to a roller block. I installed an Explorer roller block gt40 P head engine in my 83... Everything bolted right up,,, Accessory brackets, Accessories, 4 barrel Intake, pan...
The only thing I can think of that did not, are the stock exhaust manifolds and the air pipe that comes off the back of the heads to the cat......
You could use different heads than I and probably get those items to work also....
The flat tappet cam will go right in the roller block. You will need different lifters and different push rods. Other than that it should all bolt right up. The spider and dog bones (if they came with the block) are not needed.