procomp 15 degree heads???

[72'Monte]

i can get procomp 15 degree alum heads for $900.complete.also i can get a dart intake for around $400. and procomp has a shaft roller rockers to work on the heads for $300.and i spoke to a sales person and he said that flat top piston well work.the header bolt pattern is a stahl pattern.here is there ad http://store.procompelectronics.com/...embled.aspx.is there anything that i'am missing on this top end build?