Don Terrill’s Speed-Talk

are you sure about that casting number?

So it seems the 861 and 862 casting are large port Bow tie heads and can only be used on the mark 4 and 5 blocks.

Aside from that there 380 cc runner volume would call for having atleast 556 cid under them for a street usage and in a light car and with 3.90 gears out in back to make good use of that big port volume.

In other words if your not planing to build a big cid 750+ hp motor then heads with under 320 CCs will serve you far better and you can still make well over 600 hp on pump fuel!

Curious to see if this first post is a real person or a robot troll.

Looks suspicious certainly, but would anyone be trolling to shill factory GM parts?