Heads: 1G 6 Bolt vs. 1G 7 Bolt

[Jakey]

Car in question: '92 Laser, 6/4, Stock

I'd like to hear people's opinions about the 1G 6 bolt head versus the 1G 7 bolt head. I've read that the 7 bolt head is slightly better flowing and has better coolant passages, is that correct? I believe Nash is running a 7 bolt head on his car? What all needs to be altered for installation of the 7 bolt head? The reason I'm asking is because from what Jacek and I have come up with, my stem seals are shot due to the good compression (I don't remember the exact #'s) coupled with smoking at idle so therefore I'd like to have my head rebuilt this spring. The head rebuild is going to be nothing more than something comprable to the EngineTecs stage 1: http://www.engintecs.com/html/dsm_heads.html

So, stick with the 6 bolt or search for a 7 bolt?


EDIT- After some searching, I see that I would need to drill out the head stud holes from 11mm to 13mm to accept the 12mm 6 bolt head studs if I chose a 7 bolt head.

[Tsi]

I think you'll find some good info there. I know I did, good tech page.


http://www.roadraceengineering.com/1g2gheadswaptechtip.htm

[JET]

The only main differences in the 7 bolt is 1mm smaller head studs and better coolant flow. The air flow is the same. All stock 1g heads flow way more than what you are looking for Jakey. Just rebuild the one you have.

[Raptor]

What JET said ;)

[john]

I would rebuild yours also. I believe Nash's 7 bolt head is off his old 2g. Even a 2g head can be bolted up without any time consuming work. All you have to do is drill the head to 1/2" and pull the seal out of the end of the intake cam. A 1g thermostat housing even bolts up to a 2g head but not vice versa.

[JET]

I believe Nash's 7 bolt head is off his old 2g. Even a 2g head can be bolted up without any time consuming work. All you have to do is drill the head to 1/2" and pull the seal out of the end of the intake cam. A 1g thermostat housing even bolts up to a 2g head but not vice versa.
Please get you facts straight or don't post. Nash's head used to be on his 2g, but it is a 7 bolt 1g head.

[Jakey]

Please get you facts straight or don't post. Nash's head used to be on his 2g, but it is a 7 bolt 1g head.

See us Iowa folk ain't all that dumb. :D

[john]

Please get you facts straight or don't post. Nash's head used to be on his 2g, but it is a 7 bolt 1g head.

If you can read, I said I believe. That was not my reason for posting anyhow. I was adding info about the difference between the installation of heads.