can i put a 7 bolt head on a 6 bolt block?

[axloverstreet]

ok, i need new valve and internals for my 1g head.... well ive come apart a95 gst that is knocking, can i get the head off of that one, and just slap it on my 91 gsx and go with it????????? or do i need mods for that.. im new at this so thanks amillion for any help

 

[woooop]

Yes you can and you can put a 7 bolt head on a 6bolt block as well. Use the search button it works wonders!

 

[axloverstreet]

Yes you can and you can put a 7 bolt head on a 6bolt block as well. Use the search button it works wonders!

so i CAN put a 2g head on a 1g block!!?!?

 

[woooop]

Use the search button!

 

[Xit40]

Yes you can, but your going to have to enlarge the head stud holes in the head by 1mm. The 6 bolt head studs are 12mm whereas the 7 bolt head studs are 11mm.

 

[axloverstreet]

Yes you can, but your going to have to enlarge the head stud holes in the head by 1mm. The 6 bolt head studs are 12mm whereas the 7 bolt head studs are 11mm.

ok, how do i do that?

 

[fwdmaster]

Yes you can, but your going to have to enlarge the head stud holes in the head by 1mm. The 6 bolt head studs are 12mm whereas the 7 bolt head studs are 11mm.

+2 on that

 

[ArticNemesis]

Take it to a machine shop.

 

[wvturbo2]

The 6 bolt head flows better than the 7 bolt head. I wouldn't bother putting a 7 bolt on unless its just a cheap fix

 

[Dsmj89]

The 6 bolt head flows better than the 7 bolt head. I wouldn't bother putting a 7 bolt on unless its just a cheap fix

+2. Get on ebay or the classifieds and look for 1g heads, they will run you almost as much as having to mod the 2g head to make it work with the 6 bolt block.

 

[tjbiker031]

Just get your head rebuilt if you just need new internals for it. No need to buy a new one or get into a 2g conversion. OR!!!!!! give George at Kar King a call and he can hook you up with a rebuilt head for $450 or you can get a questionable one off ebay or craigslist....

 

[axloverstreet]

+2. Get on ebay or the classifieds and look for 1g heads, they will run you almost as much as having to mod the 2g head to make it work with the 6 bolt block.

ok, then in that case, i have another 6bolt head completly milled, the 7 bolt would just be a temparary fix, so will the 7 internals (valve springs, valves etc.) fit in my 6 bolt head???? and if not, whats the cheapest route to put internals into my 6 bolt head??

 

[erald01]

The 6 bolt head flows better than the 7 bolt head. I wouldn't bother putting a 7 bolt on unless its just a cheap fix

Not necessarily..... 1g intake ports are bigger but the 2g has better casting so take it for what it's worth. Other than that you can switch them as long as your use the right intake manifold. I have seen people try to use a 2g manifold on 1g head or the other way around and it doesn't work. They don't match up flange wise and create HUGE boost leaks. And the difference is 1g and 2g heads not 6 bolt and 7 bolt. The 7 bolt 1g still had the larger port head. The 2g heads have a higher velocity intake charge in comparison to the 1g head. The 1g head can flow more but doesn't necessarily depending on conditions. A 2g head should generally have better part throttle and mid range response while the 1g head should have a higher flow potential at high RPMs.

 

[idt512]

Yeah there are a lot of people that believe the 1g head flows more just because it has larger ports, but fail to realize that both heads will eventually flow through the same size intake valve anyway. The 2g heads have a better port angle to the valve and therefore achieves better flow. Now when you start getting into oversized valves its a different story...


Here is my take on this subject:

Stock valves - 2g head is better
Oversized valves - 1g head is better