7bolt head on 6bolt block

[DSMcamaro]

1.) Which intake manifold flows better, 1G or 2G? I know the 1G is bigger, but that does not necessarily mean better.

2.) After comparing a 1G head with a 2G head, and doing some research, it looks as though the 2G head is a better flowing head. I also found that the 6bolt heads have a bigger head bolt than the 7bolt heads...So If I wanted to put a 2G 7bolt head on my 1G 6bolt block, would I need to machine the head to fit larger headbolts?

3.)If I swapped on the 7bolt 2G head to my 6bolt 1G and used the stock 2G manifold, what else would i need to swap? I know the 1G throttle body is bigger but will it bolt up to a 2G manifold?

 

[Slow99x]

Sensors won't work with your computer. Most people that convert are 2gs that use the 6bolt block and retain a ported version of their stock head. It makes for easy wiring.

 

[Street Surgeon]

1G IM flows better, and really for most people on here either 1 or 2G heads will be fine. The new flavor of the month is the 2G head but the 1G has a fine rep. As for the throttlebody it will bolt up but you should port the IM if you're putting it on a 2G IM.

 

[Slow99x]

Research has shown that Evo heads flow the best and 2g heads are next( when ported correctly). The 1g is fine and it'll be more difficult than it's worth to put a 2g head on a 1g.

 

[my98GST]

I was just reading the Magnus write up and #### using a 1g head on my 6bolt... Looks liek there is a shit ton more work involved with the 1g head... Looks to me like you just bolt the 2g head on and drop it right in

 

[blcknspo0ln]

I think you're missing the biggest part. You need to bore the head to accomodate 12mm headstuds instead of the stock 11mm that come on 7bolt heads. Swapping a 1g CAS on shouldn't be a pain, but you'll also need to get a 2g thermostat housing.

 

[my98GST]

Well of course that Black, but I mean all they'll do is just stick it in the vice and bam they're done with that I'm almost having second thoughts about doing a 6 bolt swap...

 

[DSMcamaro]

I think you're missing the biggest part. You need to bore the head to accomodate 12mm headstuds instead of the stock 11mm that come on 7bolt heads.

I have a 1G 6 bolt head and a 2G head torn apart right now and I found that the larger (6 bolt) headbolts do fit in the headbolt holes on a 2G head. So is the boring still necessary just for proper alignment or what?


I'll probably just stick with the 1G head and 1G intake manifold and port both. But if i find time, I might try something new and throw some aluminum welds in the intake port on the intake and head and then try to port them the way I want to get better flow. If you look at the intake ports on a 2G head, the air flow is more directed to the base of the valve (rather than the top part near the guide like the 1G head) which would make more sense to me for better flow and would probably be the whole reason behind redesigning the 2G head.

also, while I'm throwing questions out there, Is a non turbo(4G63) intake manifold the same as turbo manifold? The 6bolt head and manifold I'm working on are both from a 91 non turbo car.

 

[Street Surgeon]

Here's the link to a comparison between the 1G and 2G IM's. Clicky.

 

[DSMcamaro]

Great link! Thanks.

 

[daren_p]

I have a 1G 6 bolt head and a 2G head torn apart right now and I found that the larger (6 bolt) headbolts do fit in the headbolt holes on a 2G head. So is the boring still necessary just for proper alignment or what?

Have you checked the 6 bolt headstuds in all the 2g's head holes? I had read that while some fit, not all will?

If I do a 6 bolt swap I will probably stick to a ported 2g head but for a 1g I would say just stick to the 1g head/intake mani/TB setup.

 

[DSMcamaro]

I checked them all and the 6 bolt head bolts all fit in the 2G head. If I have time today or tomorrow I'm going to try and bolt the 2G head to the 6 bolt block just to test it out. That way I'll know for sure. The are bolts are from a non-turbo 4G63, but i was lead to believe that they were no different from the turbo ones. Most people probably run ARP studs when they do the swap...that also might be a different story when compared to stock bolts.

 

[DSMcamaro]

So I bolted the 2G head on the 6 bolt block with no problems. Used the stock 6 bolt head bolts, didn't bore out the head bolt holes on the 2G head. So I figure I could squash those rumors.

keep in mind I just did this for testing purposes, I'm pretty sure I'm going to put a 1G head back on my car.

 

[blcknspo0ln]

Hmm. It leads me to believe that there are heads out there that are bored to different specs. Does anyone remember the thread where a 7 bolt head (1g head) got stuck on a 6 bolt block? There have been several cases about this and it sure isn't a rumor. I'm glad your experiment works, so maybe in the future we all can say that it sometimes works and sometimes does.

 

[DSMcamaro]

My buddy has some 6bolt ARP head studs,I'm going to try those too. Because who would really use stock 6bolt head bolts anyways? Well i guess some people would, but I would assume most people are stepping up to ARP.

 

[jasonlee]

I have personally put 2 2g heads on 6bolt engines, with ARP studs on both. they will fit but its extremely tight, and takes some serious wiggling to get the head to slide down the studs... its much easier if you drill out the holes just a touch (the alignment pins in the engine line up the head anyway) also, the ARP's did get stuck on one of the engines.. was very hard to get out... so if i were to do another one of these, it will definitly get drilled out no questions asked

 

[DGajre777]

1.) Which intake manifold flows better, 1G or 2G? I know the 1G is bigger, but that does not necessarily mean better.

2.) After comparing a 1G head with a 2G head, and doing some research, it looks as though the 2G head is a better flowing head. I also found that the 6bolt heads have a bigger head bolt than the 7bolt heads...So If I wanted to put a 2G 7bolt head on my 1G 6bolt block, would I need to machine the head to fit larger headbolts?

3.)If I swapped on the 7bolt 2G head to my 6bolt 1G and used the stock 2G manifold, what else would i need to swap? I know the 1G throttle body is bigger but will it bolt up to a 2G manifold?

Courtesy of SBR's website...

Block Only Swap Kit

"So your bad ass 2G needs a heart transplant. Here is the list of what you need to do the 6 bolt block swap and retain your 2G head. Your 2G head will need machined out to fit the larger 6 bolt head studs. This is sold as a full kit, and we won't split the miscellaneous pieces up unless they're on our site else where already. Some of the items listed, need your 2G parts modified, and are not included in the kit.

All parts are BRAND NEW Mitsubishi parts

6 bolt water line (filter to water outlet)
6 bolt oil filter housing
6 bolt oil pan
6 bolt oil pick up
6 bolt rear main seal
6 bolt timing belt tension arm
6 bolt timing belt cover
6 bolt water pump (OEM Replacement, not Mitsu)
6 bolt flywheel (ACT)
6 bolt front cover (OEM Replacement, not Mitsu)
6 bolt timing tensioner
6 bolt trigger plate
7 bolt front motor mount (Mount not included *needs modified)
2g counter weight on the shifter (Weight not included *needs cut off)"

http://www.slowboyracing.com/more.php?id=1053&


Full 2G 6 Bolt Block/Head Swap Kit

So your bad ass 2G needs a heart transplant. Here is the list of what you need to do the full 6 bolt block and head swap. This is sold as a full kit, and we won't split the miscellaneous pieces up unless they're on our site else where already. Some of the items listed, need your 2G parts modified, and are not included in the kit.

All parts are BRAND NEW Mitsubishi parts 6 bolt Water Pipe 6 bolt thermostat housing 6 bolt water outlet 6 bolt water line (filter to water pipe) 6 bolt turbo water lines 6 bolt oil filter housing 6 bolt oil pan 6 bolt oil pick up 6 bolt cam angle sensor (will need rewired) 6 bolt rear main seal 6 bolt timing belt tension arm 1g Intake Manifold (used) 1g Coil Pack 6 bolt timing belt cover 6 bolt water pump (OEM Replacement, not Mitsu) 6 bolt flywheel (ACT) 6 bolt front cover (OEM Replacement, not Mitsu) 6 bolt timing tensioner 6 bolt trigger plate 7 bolt front motor mount (Mount not included *needs modified) 2g counter weight on the shifter (Weight not included *needs cut off)

http://www.slowboyracing.com/more.php?id=1045&

 

[DSMcamaro]

Thanks but I've decided to stick with all 1G stuff. Just for reference, the ARP head studs do fit tighter than the stock bolts, so I would still recommend getting the head bolt holes machined a little bigger if anyone else is doing the swap.

and for the post above-Thats all 2G related. I'm a 1G.

 

[DGajre777]

Nevermind, for some reason I thought you had a 2G.