1G Head Differences

[S1eeper]

I’m trying to confirm which is which.

The 1st head is 1 I pulled myself 10+ years ago off a 1g n/t, but can’t remember if it was 6 or 7 bolt. Was on car till I found some bad damage recently.

2nd is 1 I had got shipped to me for a spare bout 6 years ago. Planed on having work done to it for a rebuild. But had been packed badly and was badly damaged during shipping.

3rd is 1 I got shipped a few days ago.

So I’m seeing different markings on the 3 and other differences inside each. Looks like all 3 have the same size head stud holes. But what has me really asking is that I just pulled all the valves from 1 & 3 and I see as pictured. I see the runners at the cam caps go deeper on 1 but not on the other 2. Also 2 of them have an extra bolt hole net to the oil feed line

 

[pauleyman]

Anything big port intake is 1g both 6bolt and 7bolt. Head bolt holes are larger on 6 bolt. All 2g heads have smaller intake ports.

 

[S1eeper]

Anything big port intake is 1g both 6bolt and 7bolt. Head bolt holes are larger on 6 bolt. All 2g heads have smaller intake ports.

Would like to say thank you. Made me go back out and do another look over. Intake is the same size so I figured I would go ahead and try drop the head on to my arp’s. Was told it was a 6 bolt head but do to it not going on the studs. More machine shop work

 

[biglady112]

Take a half inch drill bit and open all ten of the holes. Done easily enough in less than two minutes. And. Ow your seven bolt head will slide right on.