identifying my engine
 

so the engine i bought has a casting # 3970010 with date f 22 0 . the heads are # 3998993 . so , going by the mortec site .....i have a 1970 or 1980 350 block with 1972-1973 75cc heads. am i correct ? and are these heads good ? will all 350 gasket sets work or do i have to determine if i have the 70 or 80 block ? engine does have a "cam " in it. dont know what kind of cam or the specs on it. a holly 600 carb and a holly street dominator intake. headers too. sound like a good combo or should i change anything before i put it in my truck ? it appears to have been recently rebuilt like i was told it was. thanks guys. i am new to chevy's and want to get everything right before i install it. :)