Gn1 or GN1R

[Eticket]

How do you tell the difference? is there a serial number difference? or something else?

 

[forcefed3.8's]

The r's will have an R-xxx part number on the intake side.

 

[krom]

 

[Eticket]

Unfortunately, I just bought a set that are supposed to be R's, but they don't have this serial number.

Can anyone clue me into the differences? Maybe there's not enough difference for me to care.

 

[forcefed3.8's]

The R's have 2" (maybe 1.98") intake valves. I am running regular GN1's. I don't think at a high 8 sec or slower level you will see a difference (maybe faster, I will find out).

 

[Eticket]

well dang - maybe the seller honestly didn't know what he had - but they only have the 1.90/1.60 valving.

 

[bison]

The r has larger intake valve and the valves should be about .100" taller than standard Buick valves which allows for much larger double spring set ups.

 

[gnxtc2]

Aren't the exhaust ports moved on the "R" heads?

Billy T.
gnxtc2@aol.com

 

[norbs]

I would buy neither, go stage II heads, 1/2 the cost............and better cylinder distribution.

 

[gnxtc2]

I would buy neither, go stage II heads, 1/2 the cost............and better cylinder distribution.

It might be half the cost but how much abuse do they have or how many times were they repaired. There is a trickle down cost going to Stage heads.....modify intake for FI, custom throttle linkage, custom headers, custom IC piping, custom DP, etc, etc, etc.

At least with a production style head (Champion or TA), you can buy the stuff off the shelf.

Billy T.
gnxtc2@aol.com

 

[norbs]

I agree, but it also depends on the goals involved, stage II heads don;t really have the velocity for street use either, as I am finding out the hard way..........But sometimes you can find them real cheap. Donnie has done the change from small valve M@A's to Stage II heads, I am waiting on this results , if it was worth the hassle.

 

[Eticket]

So, I've got non-r heads, but still for a good deak so I'm fine. The engine build is for a street car that will make good power.

I don't know why there is a stageII head debate.. they are obviously just about only for an all out race effort. I've been around stage II headed street cars enough. and there seems to be enough results from stage II vs stage 1 style heads to confirm this isn't there?

 

[norbs]

Not sure Manny is running 7's on E85 with a single 88 and Stage II heads..........looks pretty "streetable".........

 

[278cikiller]

Not sure Manny is running 7's on E85 with a single 88 and Stage II heads..........looks pretty "streetable".........

Norbs what about your buddy's 68 Camaro up here in Toronto with a Stage II motor in it, and Stage II heads He has put 25 or 26 motors in it and cost well over $200.000 so far for his turd and it can't make even 600 HP , Well Norbs answer that one.

 

[Eticket]

Let's not turn this into a bash thread. To eash his own on heads, but both sets of heads have proven to make crazy power.

 

[norbs]

Let's not turn this into a bash thread. To eash his own on heads, but both sets of heads have proven to make crazy power.

Words well spoken Eticket, however I must respond here. The car your referring above to has had many mechanical issues non-cylinder head related, and you can;t blame the the poor dyno numbers because of the type of cylinder head used. Just out of curiosity, if 600 hp is not much to you , how much is yours making?

 

[278cikiller]

Words well spoken Eticket, however I must respond here. The car your referring above to has had many mechanical issues non-cylinder head related, and you can;t blame the the poor dyno numbers because of the type of cylinder head used. Just out of curiosity, if 600 hp is not much to you , how much is yours making?

Sorry not into the money pit any more, Do yo know some one who will bi it ? my car!. It must have made well over 750 because it crack one of the heads along the spark plugs because of one of the waste gate lines came off and the boost went pass 30 psi.

 

[2QUICK2B6]

tune has a lot to do with it an matched parts ... my lil peewee stock long block only made about 500 hp

 

[norbs]

Id' like to change my opinion, GN heads for the street/race application, STAGE II heads more race only application.

 

[Eticket]

Norbs, funny, isn't that what I said the first time? what made you pipe up?

Guys can and will choose whatever they want - but should be informed about the experiences and engine dynamics of either application for their goals. For most 99.99% of us, going the stage I route is probably less painful than the stage II headed route all things considered.

PS - a close friend is considering unloading his full - no expense spared SII headed 283 cubic inch monster if anyone is interested. it is in a street car. The motor is too much for him - he's looking to go to something more cruiser ground pounder friendly like a big BBC.