sbc heads casting numbers ?

any experts here ? i looked all over the internet and cant find out what size valves ive got , casting number is 383487 small block chevy

 

I think you're missing a number somewhere, but a "383" being the first would indicate a 55-57 265/283/327

 

Are you sure the casting number? Can't find that number.

Jim

 

i know some have 6 , some have 7 numbers , mine had 38 ( maybe 39) then a space then 3487

 

ok , going to look again

 

Those are mid 70's 350-400 SBC heads. They are usually around 74cc and they are good flowing heads. I have seen them with 1.94's and 2.02's

 

http://www.mortec.com/locatpg2.htm

 

ok , one head was missing a 7 , so the correct # is 3973487 , sounds right because the block # is 3970010 , thanks for the help guys !

 

Got this from Chevymania. Could have either set of valves.


3973487 350 68-79 1.94/1.50 2.02/1.60 76cc

 

That makes more sense! Those are good heads.

3973487....71-72...350..........1.94/1.5 or 2.02/1.6 valves, was also used on '71 350/330hp LT1, 75cc chamber

 

I will throw my 2 cents The 487 heads are made 2 ways.
ealy 487 no heat treat for unleaded
late 487X with heat treat
Van

 

how would i tell if they are "x" ? , is there an x on it somewhere ?

 

I had a set of them on a 383, ran damn fine, breathed surprisingly well for what were supposed to be undesirable 'smog' heads... in fact, still motivates my pal's 50 Stude PU very well!

 

If they are '71 LT-1 heads, They would have came with screw in studs and guide plates.

 

The 487X would be just as I type it with the X right after the 7. The 487 and the 993's are big chamber heads but are considered very good flowing and power making heads. 882's and 624's not so good.
Van

 

they do have screw in studs and guide plates , but i just assumed somebody added them later , maybe not ! the guy i bought it from did claim it was an LT-1 but i just figured he was full of shit

 

Got any pictures you could post?? I'd like to check those out. Thanks!