Sorry for the delay
You still have not said the build type and how high the RPM and why. High RPM will not get you much on a 4.6 they only flow 500 cfm at 5k and that is with the heads off. The TFH are the best out there BUT.. NA you can only get 330 HP out of 4.6, it is a waste.
Yes, yes TFH has this graph and that chart but the results are hard to duplicate and that build is going to need PRO level rebuilds frequently to keep you happy.
They work much better on a bigger engine like a 5.4
Look at the hoops Ford jumps through on the Coyote to get high HP and high RPM, that's a lot of effort. It comes in at 1.5 HP/CID, and what is the longevity? My buddies are having problems at 35k miles and they are not racing them.
Using the same big cam and jumping from the PI manifold to the Edelbrock I lost torque and gained 10 HP while moving the peak up 500RPM = BFD.
The valve guide are PM on the TFH and I had one fail turn into a million micro bb's
bounce back up into the manifold and take out 7 cylinders. No response from THF...none, no calls, emails, nothing they do not want to talk to end users and I do not blame them in a way. After months I called Summit and sent them back and heard nothing...I had moved on to another head project and come home one day to find a new set of TFH on the porch, but still no contact or updates???
The PM valve guides are a long taper design and for but are fragile to vibration? You must but the Track Heat heads to get the cnc machining and bronze guides and pay more. Pushing out a PM guide is going to be a PITA, some will shatter, but it easy to do.
Put the heads in a 300 degree oven and push then out backwards, takes 5 minutes.
Now what do you do about the new ones? Type, length, size, are you going to knife edge them before you put them in? Nope just slam them in and go. How are you going to size them? And why, you still have not said the engine build and this is the same question MMR is going to ask and you want the high RPM set up and find out it is loose and noisy, drives shitty on the street and now you hate MMR. Been there done it and it will run nice when you get it hot enough to swell up the guides and piston rings but until max pressure is applied..
What kind of valves? TFH are big but cheap, how much clearance for your heat range the build will make, NA or FI? Totally different clearances must be made through out the total build. What happens when it gets hot or really hot?
Fastest cheapest way, get the Track Heat heads and skip the MMR BS.
This is why an engine for the street starts at 14,000 from L&M...it's worth it. By the time I am finished with a build it cost me 13,000 I should have payed the extra 1000 and saved the time and agrevation.
GOT FLOW?
See that silver pin, that is a pin gauge and the only way to check your honing size, here I am done and putting the cross hatching on the guide after cutting with a straight flute reamer..Lots of tooling required and you MUST have a plan on why you are doing that way so you can amake changes and get it right the next build.
I have done 3 Cobras and 13 street race engines and I showed all the time and money wasted here somewhere.
I done, it's been fun but I am chasing the unicorn like you and they do not exist.
