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Roller rockers

Well, then you need to deal with the pushrod interfering with the port...

Yup, my 3/8" push rods just clear the ports in my 906 heads.
And i am not sure how much you could remove from that before ending up in the intake.
As far as i know it is acceptable to grind a tad off to ensure the push rod clears the wall but thats it.
 
We had to put my Isky arms in the lathe to narrow them up.
 
I bought a set of new-never-used Iskys in the 80’s off of a local Mopar guy for $100. Rockers, adjusters, separator springs.
I already had a set of Crane iron rockers on my 440 at the time, but the price was right.
Fast forward about 15 years and I dig them out to use on my 383.
The bodies were much wider that the Cranes, which made the tip to valve alignment way off, plus the the space between the two rockers was greatly reduced, to the point where the separator springs wouldn’t fit between the rockers.
I used an old Crane rocker as a template for where/how much to whittle down the Isky’s.
They were pretty chunky too , compared to the Cranes, so they went on a diet.

It’s the only set of Isky’s I’ve put on anything, and don’t know if the width issue was because they were an early set or what.
They probably would have fit an early set of heads that used the aluminum bolt on stands, which as I recall are narrower than the stamped shaft hold down clamps of the later heads.

I liked that the Isky body was wider. When I got mine, 43 years ago, I modified the hold downs and cleaned-up the stand a little and inserted a shim between the stand/hold down and the rocker body. Pitched the springs and made spacers for between the rockers.

This was after I sent my Crower rockers back to Dave Crower. They looked like the Crane ductile iron rockers, but with an interference fit adjuster (no lock nut) that was a unique thread pitch.
 
So, the way I read this is..... if I want to bad enough, it can be done. I would just need to machine the rockers narrower, maybe modify my aluminum stands, and machine some custom spacers. Piece of cake.
You'd have to tweak the rocker sideways.. or haha maybe just re-locate the valves...and if you had the ultimate "T.V. repairman" set of tools I bet you could spread the cam lobes and lifter bores out a tad:D:D:D

Wimpy-block rockers
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Mighty-block rockers
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Did you select the cryogenically treated ones?
It says close to 600# is about the limit, yet the treatment gives 2-3 times more strength compared to non treated which seems to be beneficial even for say 400-500#....or would it be over kill?

Regular ones. I'm running around 400lbs open and haven't had any issues.
 

Hard to believe you get quality for that price.
Though it might work fine when using with not too high valve spring pressures.
Just wonder about the machining tolerances on the rocker shaft and rocker arm bores and what's left of it after 100hrs of operation.
Stainless steel would not be my choice of material for those parts.
 
Perfect timing for this discussion as I believe I will be having to replace the 1.6 PRW rockers in one of my motors that has Trick Flow 240 heads. So my take on what you guys are saying, and correct me if I am wrong. The only real choices are:
Harland Sharp 70016KE for $965.99. Disadvantage to these is the needle bearings that we really don't need.
Mancini - Harland Sharp 57001-16-714K for $511.95. These don't have needle bearings, but I think would need hold downs unless I can reuse mine.
Hughes 15203 for $750.90 plus hold downs at $99.95 if I can't reuse mine.
 
Perfect timing for this discussion as I believe I will be having to replace the 1.6 PRW rockers in one of my motors that has Trick Flow 240 heads. So my take on what you guys are saying, and correct me if I am wrong. The only real choices are:
Harland Sharp 70016KE for $965.99. Disadvantage to these is the needle bearings that we really don't need.
Mancini - Harland Sharp 57001-16-714K for $511.95. These don't have needle bearings, but I think would need hold downs unless I can reuse mine.
Hughes 15203 for $750.90 plus hold downs at $99.95 if I can't reuse mine.

Yes. I would add Comp Cam's Pro Magnum's as an option.
 
As for the 273 rockers on a BB, along with not having any offset, I think you’re going to find they are too short.
Easy enough to tell by putting them next to each other on a shaft.
 
Perfect timing for this discussion as I believe I will be having to replace the 1.6 PRW rockers in one of my motors that has Trick Flow 240 heads. So my take on what you guys are saying, and correct me if I am wrong. The only real choices are:
Harland Sharp 70016KE for $965.99. Disadvantage to these is the needle bearings that we really don't need.
Mancini - Harland Sharp 57001-16-714K for $511.95. These don't have needle bearings, but I think would need hold downs unless I can reuse mine.
Hughes 15203 for $750.90 plus hold downs at $99.95 if I can't reuse mine.
Why do you think you have to replace the PRW's?
 
Why do you think you have to replace the PRW's?
Maybe I don't, idk. Apparently the builder didn't tighten down several of them and I have ran it for 1500 miles like that. 2 of the adjusting nuts were laying in the head. Several of the adjusting screws are galled or the threads messed up preventing them from being removed. 1/2 the lifters in the motor collapse with a gentle push of the finger. I'm really not sure what damage has been done. The Trick Flow heads are made so you can't pull lifters to inspect/replace. This is the motor that I specified HS rockers originally, but he installed these PRW's instead. With all this talk of inferior Chinese rockers, I really don't know if I want to use them again....
 
I liked that the Isky body was wider. When I got mine, 43 years ago, I modified the hold downs and cleaned-up the stand a little and inserted a shim between the stand/hold down and the rocker body. Pitched the springs and made spacers for between the rockers.

This was after I sent my Crower rockers back to Dave Crower. They looked like the Crane ductile iron rockers, but with an interference fit adjuster (no lock nut) that was a unique thread pitch.
I started machining some Isky rocker spacers for a 440 but all that got put on the back burner many years ago as life got in the way plus I was more or less working 3 jobs. One job was building engines and rear ends for others, my wife's furniture sales/rental store and my regular job in a refinery as a machinist. No wonder my back is shot these days. :(
 
Hard to believe you get quality for that price.
Though it might work fine when using with not too high valve spring pressures.
Just wonder about the machining tolerances on the rocker shaft and rocker arm bores and what's left of it after 100hrs of operation.
Stainless steel would not be my choice of material for those parts.
SS is pretty tough depending on the grade......but if those are China made.....the grade is probably rock bottom.
 
I have a set of customer supplied PC2337-1.5 rockers in the shop right now. I'm going to suggest he hire a professional baseball player.......pitcher or outfielder.......and have them throw those rockers as far as they can into an ocean. If that is a bronze bushing in the housing it is the strangest color I have ever seen. The lash/preload adjusting screws are either almost too tight to turn or so loose they wobble, and the lock nut/jam nut mating surface on the rocker body isn't perpendicular to the adjusting screw. Tighten that nut up and you may eventually have an adjusting screw break.

Oh.....Plus the roller tips are not parallel with the rocker shaft. You get some very strange contact patterns on the valve tips.
 
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SS is pretty tough depending on the grade......but if those are China made.....the grade is probably rock bottom.

The metallurgy/strength of rocker body is the least concern.
 
I bought a set of new-never-used Iskys in the 80’s off of a local Mopar guy for $100. Rockers, adjusters, separator springs.
I already had a set of Crane iron rockers on my 440 at the time, but the price was right.
Fast forward about 15 years and I dig them out to use on my 383.
The bodies were much wider that the Cranes, which made the tip to valve alignment way off, plus the the space between the two rockers was greatly reduced, to the point where the separator springs wouldn’t fit between the rockers.
I used an old Crane rocker as a template for where/how much to whittle down the Isky’s.
They were pretty chunky too , compared to the Cranes, so they went on a diet.

It’s the only set of Isky’s I’ve put on anything, and don’t know if the width issue was because they were an early set or what.
They probably would have fit an early set of heads that used the aluminum bolt on stands, which as I recall are narrower than the stamped shaft hold down clamps of the later heads.
I used the regular crane golds on the aluminum stand maxies and they fit like any other head.
 
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