Push rods with GN1's

[boostmaster]

Even the GN1 heads with stock style rocker pedestals? Didn't think you could not use stock shafts on them.

 

[boostmaster]

iron heads and Aluminum GN1's use different rocker arms. You cannot change them back and forth
Mike

So the GN1 heads with stock style shaft pedestals don't accept factory shaft rockers? I was under the impression that they could use both.

 

[pacecarta]

you can use stock rocker shafts on aluminum gn1 heads because the valve contact point is wide
, but roller rocker shafts designed for GN1 wont work for irons and vice versa

 

[boostmaster]

Ok now I'm really confused, so how do you identify roller rockers designed specifically for GN1 heads?

 

[bison]

Ok now I'm really confused, so how do you identify roller rockers designed specifically for GN1 heads?

The spacers are different/oriented a little different

 

[Mike Licht]

The valve spacing in the GN1 aluminum is wider than the stock iron head. The stock rockers have enough slop/play in them to fit just fine on the GN1 head. Roller rockers on the other hand do not. The 8 bolt head takes a special offset roller rocker that is made for Champion. We usually try to get out customers who buy aluminum heads to get the 14 bolt version since they still bolt on fine but the roller rockers are MUCH less expensive since they use the stud style. The Harland Sharp rocker will not fit on the aluminum head
Mike

 

[gnbeginer]

hmmm - my GN1 heads have screw it studs and individual rockers like a sbc.

 

[turbofabricator]

Two versions of the GN1 head stock and 14 bolt version. 14 bolt version uses individual rockers, like the SBC. Push rod length is VERY important to get SPOT ON! just guessing is leaving alot of power on the table, and or broken parts. For more adjustability, I slot the oil feed hole in roller rockers. Simple if you take your time and know what you are trying to accomplish. Seems EVERY part I buy needs some of my special re-work. Hey!.........I've UPPED my standards.........so UP YOURS! The T&D rockers require a .100" shorter push rod. Every engine gets measured and checked. You can buy 12" digital claipers at Harbor Freight for less than $50 I think. stock rockers have serious problems of their own. The shafts break real easy, and the ratio is not fixed due the the sloppyness of them. (variable ratio) I've seen them burn the fulcrum, too. (friction)

 

[ek02]

The valve spacing in the GN1 aluminum is wider than the stock iron head. The stock rockers have enough slop/play in them to fit just fine on the GN1 head. Roller rockers on the other hand do not. The 8 bolt head takes a special offset roller rocker that is made for Champion. We usually try to get out customers who buy aluminum heads to get the 14 bolt version since they still bolt on fine but the roller rockers are MUCH less expensive since they use the stud style. The Harland Sharp rocker will not fit on the aluminum head
Mike

If you use the 14 bolt GN1's, order a set of ARP rocker studs for those Scorpion rockers. Part #ARP-200-7201 from Summit. You have to buy 16. Same as a 7/16" Chevy stud. The studs that come from Champion are prone to breakage, especially if your valve springs have a lot of pressure.

 

[Mike Licht]

Two versions of the GN1 head stock and 14 bolt version. 14 bolt version uses individual rockers, like the SBC. Push rod length is VERY important to get SPOT ON! just guessing is leaving alot of power on the table, and or broken parts. For more adjustability, I slot the oil feed hole in roller rockers. Simple if you take your time and know what you are trying to accomplish. Seems EVERY part I buy needs some of my special re-work. Hey!.........I've UPPED my standards.........so UP YOURS! The T&D rockers require a .100" shorter push rod. Every engine gets measured and checked. You can buy 12" digital claipers at Harbor Freight for less than $50 I think. stock rockers have serious problems of their own. The shafts break real easy, and the ratio is not fixed due the the sloppyness of them. (variable ratio) I've seen them burn the fulcrum, too. (friction)

Ken,
you need to be very careful when using a caliper to measure pushrods. The largest manufacturer of them does not measure them "end to end" they are measured 120* on the radius because of the oil hole. On more thn one occasion I have had a customer call and special order a pushrod that was not the exact length he though he was getting and got stuck with them. The tool they sell works well and leaves little room for error

 

[MDavis]

Ken,
you need to be very careful when using a caliper to measure pushrods. The largest manufacturer of them does not measure them "end to end" they are measured 120* on the radius because of the oil hole. On more thn one occasion I have had a customer call and special order a pushrod that was not the exact length he though he was getting and got stuck with them. The tool they sell works well and leaves little room for error

Mike,
Rather than start a new post. I'm looking for the correct length push rod.
I'm running...
208/208 flat tappet cam
Seal power lifters
Champion iron heads stock bolt
Stock rockers and pushrods want to use my TD rockers

Ready to order.

 

[Jay J]

Ken,
you need to be very careful when using a caliper to measure pushrods. The largest manufacturer of them does not measure them "end to end" they are measured 120* on the radius because of the oil hole. On more thn one occasion I have had a customer call and special order a pushrod that was not the exact length he though he was getting and got stuck with them. The tool they sell works well and leaves little room for error

X2 Get the push rod checking tool from Mike or others and nail it the first time. Your caliper will give a different length due to what Mike explained above. You will be glad you did it this way instead of twice...