All Big Six Ordered the Scorpion 1059 Roller Rockers

Relates to all big sixes

HitmanX

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AH, yes makes total sense now regarding the heights. I can do some measuring to help and post my findings regarding my seat wear and installed heights.

Probably going with 5/16" 0.080" wall rods from Smith Brothers, if I ever cam this thing it will not be radical enough nor turn enough RPM to worry much about rod deflection. I can keep you guys posted for turn around time and cost. Stock pushrods appear to be 10.140" by my research for the EFI and the 10.250s give us 0.110" extra length to make up for the new rockers as they are BBC units. Correct?

M-6529-A302 is the FMS pedestal rocker shim kit, these run about $13 shipped. Going to pick this up in the event I need them.

If these questions are not related to this thread, please let me know and I can remove this and make another thread.
 

efloth

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AH, yes makes total sense now regarding the heights. I can do some measuring to help and post my findings regarding my seat wear and installed heights.

Probably going with 5/16" 0.080" wall rods from Smith Brothers, if I ever cam this thing it will not be radical enough nor turn enough RPM to worry much about rod deflection. I can keep you guys posted for turn around time and cost. Stock pushrods appear to be 10.140" by my research for the EFI and the 10.250s give us 0.110" extra length to make up for the new rockers as they are BBC units. Correct?

M-6529-A302 is the FMS pedestal rocker shim kit, these run about $13 shipped. Going to pick this up in the event I need them.

If these questions are not related to this thread, please let me know and I can remove this and make another thread.
I would go with the 3/8 pushrod if you are ordering them custom. They fit no problem on my 1991. I found 5 of the 6 retainers, I must have dropped one and it rolled away somewhere in the shop.

If you look at the picture I posted with the springs installed, The exhaust retainers end up sitting lower on the valve stem so exhaust springs are compressed more than the intake springs when the valve is closed. It does not affect the stem height AFAIK.
 
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Pontus

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I am using a 320k mile head, surely there is going to be seat and valve wear I would imagine. Figured the shims will get me to the correct installed height like I did on the Powerstroke. Those were all over the place!

With the Qualfast retainers, will that change OE exhaust installed height or simply eliminate that rotator?
The EFI valve tip to groove is .25 on the intake and .29 on the exhaust. If you use .050 up locks, your exhaust retainers will only be .010 over the intake, or you can use .030 up retainers and be .010 under. .040" on 300#/in springs is 12lbs difference.
 

HitmanX

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Eyeballing Post 56, seems I will need to measure the diameter of the spring seat to find shims that will work. The OD of the 903 is a 1.400" so the kits with 1.437" OD from Comp (4754) and Jegs (555-20591) are close but no cigar due to ID at 0.645".

Will price out 5/16" versus 3/8", but glad to know the large fit just fine and will probably follow suit. No worries on five of six retainers, still five more than I had previously. I can probably turn one up somewhere if yours does not in the shop, no rush and I appreciate you finding them!

Also going to keep measuring and thinking what is the best way for me to go. Efloth and I are both on the stock camshaft if that is a deciding factor for which way to point me. Leaning toward popping on six intake retainers on the exhaust side.

Ordered my 903s and the FMS shims. Forgot picked up some Felpro Viton stem seals when I ordered a bunch of other crap in April, so it will receive those while in there. The OE ones are probably dried out anyway from sitting 14 years.
 

pmuller9

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You shouldn't need valve spring shims but just in case:
The Elgin VSA103HP, VSB103HP and VSC103HP have a 1.500" OD and a 1.031" ID. and are .060", .030", and .015" thick respectively.
 

THE FRENCHTOWN FLYER

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Stock pushrods appear to be 10.140" by my research for the EFI and the 10.250s give us 0.110" extra length to make up for the new rockers as they are BBC units. ..
BBC rockers do not have optimum geometry so if you haven't procured them rethink that. They will work but Chevy six rockers are a better choice.
 

HitmanX

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Hmm, well glad I just ordered springs and such.

Harland Sharps for what specific application?
 

pmuller9

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Harland Sharps for what specific application?
My apologies. We should be talking about about pedestal mount rocker arms for the EFI heads instead of the stud mount Harland Sharp or BBC for the earlier 1965 to 1984 heads.

Are you going to use the Scorpion roller rocker arms?
 

HitmanX

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Yes, my plan was to follow suit as Efloth did on his.

My engine is a 1992 model EFI, pedestal rockers.
 

Frank

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AH, yes makes total sense now regarding the heights. I can do some measuring to help and post my findings regarding my seat wear and installed heights.

Probably going with 5/16" 0.080" wall rods from Smith Brothers, if I ever cam this thing it will not be radical enough nor turn enough RPM to worry much about rod

Hitman, what is the part # of the Smith Bros rods you're getting? I looked on the site, not sure which would be correct. 5/16" @ .083 wall made from that good steel will be plenty for my build also.
 

HitmanX

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I have yet to order, I want to verify the 10.250" are correct for my application as I figure custom rods have no return policy! So, I need to order the checking tool and check it out when home with all the bits.
 

Frank

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I have yet to order, I want to verify the 10.250" are correct for my application as I figure custom rods have no return policy! So, I need to order the checking tool and check it out when home with all the bits.
I got 'cha. . You're running stock short valves? Did you decide on which rocker arm? There's not much to choose from with pedestal mounting. Anything is better than the factory "skid plate" rockers IMO. Wonder if there are any 1.6 ratio trunnion bearing rockers to fit the pedestal head?
 

pmuller9

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Wonder if there are any 1.6 ratio trunnion bearing rockers to fit the pedestal head?
If you are willing to convert the head using screw-in rocker studs then you can use the 1.6 ratio Harland Sharp roller rocker arms.
What year is your head?
 

HitmanX

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Going with the same 1.73:1 Scorpions as the original poster has installed.

Motor is all stock I figure. At least all gaskets were leaky, greasy, and I think the valve cover had Ford on it somewhere. So should be stock valves still. Another plus with full roller rockers is a friction loss which should lower oil temps a hair.

Once I receive my spring tools back from a pal, I will eyeball current installed height. I figure valves or seats will have quite a bit of wear at 320k
 

Frank

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If you are willing to convert the head using screw-in rocker studs then you can use the 1.6 ratio Harland Sharp roller rocker arms.
What year is your head?
It will be a new EFI head. I assume I have to stay with pedestal for the low valve cover / stock intake? I would rather have studs, but will be using the factory intake.
 

pmuller9

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It will be a new EFI head. I assume I have to stay with pedestal for the low valve cover / stock intake? I would rather have studs, but will be using the factory intake.
You might be right about intake manifold to valve cover clearance.
How much clearance is there normally?
 

Frank

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You can always make a spacer to gain some clearance height.
Good Sunday morning Bubba. I could make a spacer, but unlike many of you, I don't have the tools or experience fabricating that sort of thing. So I am hoping that long Chevy valves, a raised pedestal and Scorpion rockers will fit under the EFI valve cover without contact. If not, spacing it is.
 
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