Quote Originally Posted by keotie View Post
Is there a block or head modification required to use the late model heads on the earlier block?

No you can bolt the vortec heads on the early block but you must use the correct intake for them (2114). Also use the correct rockers for the heads you are using. Check your rocker angle for the correct pushrod length. If you use a more exotic roller rocker then talk to a machine shop about what must be modified.