[BRUCE#14]

what is a good site to look up casting numbers and horse power ratings for stock heads . i have some 487x heads i am trying to find out about

 

[onovakind67]

http://users.erols.com/srweiss/tablehdc.htm

 

[Blazin72]

The 487x is a 75cc chambered head. I believe they're a truck head but they could have been used in low compression car applications as well. These were the same heads I pulled off the original 350 from my 72 Blazer. They're over at my dads house right now but I believe the ports are fairly small.

 

[MI2600]

The 487s were also used, in the 2.02" version, on the early LT-1 (350hp). They're good heavy castings.

 

[Blazin72]

I wonder what the difference is between a 487 and a 487x head?

 

[bigbadbowtie]

mortec.com

3973487....71-72...350..........used on 71-72 350 LT1, 75cc chamber
3973487X...71-72...350..........75cc chamber

 

[CNC BLOCKS NE]

The X heads have a bigger intake runner I believe