roller cam or flat tappet?

What is the intended use and goals for this motor? What year block? Need a bunch more info before you can really decide which way to go. Is the block tubed or bushed?
dont know what you mean by tubed or bushed. not an expert on building motors . i bought the engine from someone years ago. it was rebuilt with kb pistons, eagle crank and rods. thats all i know about it. ig was a shortblock. gona be a manual brake ,manual steering car