Cylinder Head question

[nightracer91]

O.k. I was thinking of buying my buddy's 1G 7-bolt head to rebuild and drop on my 6-bolt block. Do all of the 1G heads have the same flow characteristics or will the 1G 7-bolt head not flow as well as the 6-bolt head. Please Reply

 

[cecil722]

A stock 1g head will outflow a stock 2g head.

 

[92awddsm]

The 1g 6 bolt and 1g 7 bolt heads are one and the same. There was no change to the head other than cams on the 1g so you will be fine.

 

[nightspeed87]

The 1g 6 bolt and 1g 7 bolt heads are one and the same. There was no change to the head other than cams on the 1g so you will be fine.

what was different about that cams?
Does this have anything to do with why some 1gs got rated 190hp
and some were rated 195hp?

 

[nightracer91]

A stock 1g head will outflow a stock 2g head.

I know that but who said anything about a 2g head.

92awddsm, aren't the head studs the same also. What is different about the cams because I was thinking about using the ones that will be coming with the 1g 7-bolt head.

 

[92awddsm]

I know that but who said anything about a 2g head.

92awddsm, aren't the head studs the same also. What is different about the cams because I was thinking about using the ones that will be coming with the 1g 7-bolt head.

I dont remember exactly but I think the 93 had the best cams. I would do a search for stock cams and see if you can find some info.

The studs are different between the 1g 6 bolt and 7 bolt but the hole diameter in the head was the same. There are no mods needed to put a 1g 7 bolt head onto a 6 bolt block.

 

[nightracer91]

I dont remember exactly but I think the 93 had the best cams. I would do a search for stock cams and see if you can find some info.

The studs are different between the 1g 6 bolt and 7 bolt but the hole diameter in the head was the same. There are no mods needed to put a 1g 7 bolt head onto a 6 bolt block.

Ok I will do some research about the cams. So, the head should bolt right up. Should I use the 6-bolt studs or the 7-bolt studs.

 

[brute]

You really need to see if they have stretched. You will more than likely have to buy new head bolts, and since ARP head studs are almost the same price, you might as well upgrade.

 

[nightspeed87]

I dont remember exactly but I think the 93 had the best cams. I would do a search for stock cams and see if you can find some info.

The studs are different between the 1g 6 bolt and 7 bolt but the hole diameter in the head was the same. There are no mods needed to put a 1g 7 bolt head onto a 6 bolt block.

actually i think the 6bolt head is 12mm studs ,and the 7 bolt is 11 because I have a 7bolt head on a 6bolt block. But technically you should still be able to screw them in and it will work the 1mm difference in the thread hole when you screw it in Id assume.

 

[92awddsm]

actually i think the 6bolt head is 12mm studs ,and the 7 bolt is 11 because I have a 7bolt head on a 6bolt block. But technically you should still be able to screw them in and it will work the 1mm difference in the thread hole when you screw it in Id assume.

Technically, you are right. The 6 bolt block uses 12mm studs or bolts and the 7 bolt uses 11mm. The head has nothing to do with the size of headbolts the block accepts. Some of the 2g 7 bolt heads require reaming of the bolt holes for proper clearance with the 12mm studs but all of the 1g heads have the same bolt hole diameter and the 1g 7 bolt head is a direct interchange with the 6 bolt head.

 

[perley03]

Just one question....Why, why, why WHY????? Why would you want to put a 2G head on a 6 bolt block....The 1G head outflows the 2G by alot. This makes no sence to me at all. And what power difference are you going to get by doing all this work? Not much at all.

EDIT: Sorry i mis-read. I thought you were putting a 2G head on a 6bolt block but its a 1G 7bolt head. My bad.

 

[nightspeed87]

if your putting another head while your at it would be a good time to maybe get a port and polish job done and port and matched manifolds, thats what I did and the engine will flow so much more effeciently.

 

[nightracer91]

Yeah, I plan on putting new valves, guides, and seals in it, then get a good valve job done to ensure sealing.