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Ford Racing has a bolt-in, yup, no machining, roller rocker coversion for the 351C.

part # M-6564-C351

Pricing at a Ford Racing dealer - only those can sell this part - is $375

At JEGS or Summit is about $370

I still am waiting for my heads to return from my machinist so I have not installed the rockers. I'm a bit concerned about the mounting bolt length, as the new ones are about 7/32" longer. Can't check this with the heads still at the shop, though.

Has anyone else installed these rockers? Any advice?

I am assuming - yea, I know..... - that Ford knows what they are doing and this is a plug-n-play upgrade. Just wanted the rest of you know about it.

Larry

UPDATE: 7-11-09

The install went fine. I found I needed to purchase the shim kit for this installation to get preload set-up correctly.

LINK HERE:

http://tinyurl.com/l2ymob

While usually hydraulic lifters do not need any shimming for such pre-load, this conversion does. It adds a time consuming step to the install, but is just time and thinking, not rocket science. I found the pedestals and shims varied in dimensions, and had to spend considerable time mixing shims and pedestals to get things correct. The last two rockers, I couldn't get the right combo with the shims I had left over, and had to do MILD sanding of the pedestal bases using a hard flat surface and crocus cloth. I've put 1000's of miles on the car now, with no problems.

My engine builder, who is THE Ford guy in Fresno and does everything from 4-banger turboed Offy engines to full blown tractor pull aluminum Arias blocks, said for my engine there was no need for the larger stud, machining-necessary, roller rocker conversion. I trusted him, and am happy with the conversion.

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Last edited {1}
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...I would be more concerned with the bolt diameter!! At 5/16", how many revs do you think they will take before it snaps off at the threads? I went to roller rockers; but did it the 'Right' way and machined the pedestals down and drilled and tapped for 7/16" Chrome-Moly Studs (Morroso) with their smooth shoulders and Large Fillets, Near 'Bullet Proof'!! I see NO need for stud girdles...
You need to stay close to stock with the spring rates. The bolt and the pedestal are more vulnerable to failure as you up the spring rates.

I don't know where the danger level is spring rate wise but lets just say they are for a 6,000rpm engine.

You may need to adjust the "bolt downs" with the shims provided. Especially if you are cutting the valves.

They are a good way to go for the average enthusiast.
Larry, you purchased some good rockers, I'ved used them on my own Mustangs, and installed them in cars belonging to others, no failures. Ford has sold them for decades. I believe they're actually Crane rocker arms, just anodized blue instead of gold. Anyway, they're billet, not cast, good stuff. These are the rocker arms I am always recommending others to install. Those rockers and their allen head cap screw will easily "clamp" the spring pressures of the springs specified with ANY hydraulic cam, without worry. You see Ford hires these guys called engineers, and they do stuff like specifying bolts. The thinking goes like this: Non-adjustable rocker arms.....hydraulic cams.....lower spring rates....5/16" cap screw. Adjustable rocker arms ... solid lifter cams...higher spring rates...7/16" studs.

There's 2 considerations: the threads of the bolt/stud pulling out of the head, and side forces flexing the bolt/stud. The 5/16" threads have proven over the years they do not pull out of the heads in applications with hydraulic cams. With the mondo spring pressures encountered with some solid cams, yes the 7/16" threads are required. Side forces with the adjustable rocker system are applied directly to the stud, thats why that nice big radius is required at its base. BUT side forces with your rockers are applied to the pedestal, NOT the 5/16" bolt. The pedestal is plenty beefy. All the bolt has to do is keep the assembly clamped together and not pull out of the threaded boss in the head.

The shims mentioned are to raise the rocker arm to achieve correct geometry, they go between the rocker pedestal and the slot in the head. When all is said and done, you may need new push rods, you won't know until your heads are back and mounted on the motor, the rockers are all set for best geometry.

Anyway, the stock rocker arms are junk, and you have purchased the correct replacement.

That's great advice about how to save $70 bucks, very nice of you to share that.
Last edited by George P
I had a set of these rockers on my 4V closed chamber heads. The problem that I had was that I ended up having to buy adjustable push rods to get the valve lash adjusted correctly. Once they were set up, I never had any problems and put at least 50k miles on them. They were taken off last year when I upgraded to CHI aluminum heads, which had screw in studs.
quote:
I had a set of these rockers on my 4V closed chamber heads. The problem that I had was that I ended up having to buy adjustable push rods to get the valve lash adjusted correctly. Once they were set up, I never had any problems and put at least 50k miles on them. They were taken off last year when I upgraded to CHI aluminum heads, which had screw in studs.

Valve lash? Sounds like you were using solid lifters. This specific kit is designed for hydraulic lifters only.

Now these rockers - just the rockers - are also used with the stud (7/16") conversion. Is this what you had? I can understand a push rod length issue with solid lifters.

I'm confused by your post - can you clarify?

Thanks,

Larry
quote:
Originally posted by LF - TP 2511:
quote:
I had a set of these rockers on my 4V closed chamber heads. The problem that I had was that I ended up having to buy adjustable push rods to get the valve lash adjusted correctly. Once they were set up, I never had any problems and put at least 50k miles on them. They were taken off last year when I upgraded to CHI aluminum heads, which had screw in studs.

Valve lash? Sounds like you were using solid lifters. This specific kit is designed for hydraulic lifters only.

Now these rockers - just the rockers - are also used with the stud (7/16") conversion. Is this what you had? I can understand a push rod length issue with solid lifters.

I'm confused by your post - can you clarify?

I have a hydraulic lifter cam, but with the piston on TDC and with both valves closed, the rockers were too loose. I know that with a hydraulic set up, you just tighten it down, but it didn't work for me with these rockers. It could have been my spring set up. They might work fine for your set up, but they didn't for mine without the adjustable push rods.

Thanks,

Larry
Finished the roller rocker install this past weekend - tedious and time consuming, but not difficult. To call them "bolt in" is a bit optimistic. Roll Eyes

Haven't driven yet, but motor starts, makes no funny noise and leaks no fluids. Some tune up work, install a bunch of pieces still on the floor and workbench, and go for a drive tomorrow or Friday, time permitting.

Larry

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