Hey guys, i've been looking around an i just wanna make sure what i got is what the internet is saying...always gotta double check. so this is what i found.

Heads casting : 462624
Block Casting: 8870010 or 3970010 (i'll post pic, hard to make out)

I've gotten mixed readings over these. The guy told me they were 2.02 heads and a 4 bolt main block. Let me know what you guys come up with.

[IMG]file:///K:/DCIM/100MEDIA/IMAG0031.jpg[/IMG]

 

The block casting is 3970010. It's the most common 1 piece RMS, 4" bore block cast, used in everything from trucks to Corvettes. They were finished with 2 bolt or 4 bolt mains, depending on the application. It really doesn't make any difference either way.

462624 heads are large chamber smog heads from the 70s, with lightweight castings that love to crack. Someone may have put 2.02 valves in them at some point, but they're still garbage.

 

Ape's correct. The block is fine, its just a generic 2pc seal block with 4" bore (302, 327, 350... 99% were 350ci). Its fine for an engine build. The heads are junk. Toss them. Low compression, crack prone, poor flowing even with big valves. Junk.

 

right on so i guess its head hunting for me... Thanks alot guys. motor was recently rebuilt (probly just new rings and bearings), but donno why he would throw a set of junk heads on a fresh motor like that. but i guess i'll have to fix his mistakes with a good set of heads... any recommendations? i'm new to chevy's so don't really know whats what yet. I want a nice little street monster. nothing to fancy. 300-350 to the wheels would be nice. let me know what you guys think.

 

L31 'Vortec' heads. Casting number 906 or 062.

 

what is so good about the vortec heads? what advantage do they have over other heads? just wondering cuz alot of ppl say vortec or nothing. I would have to justify buying these heads cuz it would mean a new intake and carb to go with it. i've read that they flow a bit better then other heads but is that it?

 

They've got a better intake port design and combustion chamber design.

 

Yep, this. The intake ports are tall and narrow, so they breathe well while keeping mixture speed up, and the combustion chamber design promotes a very fast and efficient burn. Translation - more power, better fuel economy at the same time.