Putting together a set of loooow-$ cyl. heads for my sons 318 powered bracket car. Would like to run the stocker heads before we upgrade to another set that has fresh guides, VJ, hardened seats and porting. So I'm trying to avoid the machinist bill to actually doing this right......

cam lift, exhaust, is .507 on the exhaust and right now that is what the retainer-to-seal distance is (actually .504). So, I obviously need to cut the "height" for clearance. I'm thinking .100 clearance if memory serves me right?

Most of the cutters I see are for cutting the width to go to positive seals or whatever. See attached. Or do they cut height also? Or is this something that is done on a vertical mill?

This is for standard 3/8th valves and stock seals. The valves measured .370 and guide width was .630.

http://www.summitracing.com/parts/cca-4718
http://www.summitracing.com/parts/cca-4734

What you have listed there is a valve spring "Seat" cutter and an arbor.

I believe the valve guide O.D. cutters also cut the top of the guides, which the Mopars need to run aftermarket seals because they have such a long chamfer.

There are also valve guide "Topper's or Spot Facer's" available to just shorten the guide.
Or it can be done on a mill if you have access to one.

I have always recommended .080" - .100" clearance between the top of the seal to the locks/retainer. O.E.M. guide O.D. is spec'd @ .625" but we know how some of those O.E. tolerances go

When you top the guides just be sure there is enough guide height left to properly seat the valve seals of choice.

If you decide to cut the guide O.D. down to let's just say .530" find a junk head to cut and measure the actual finished cut. I have seen these cut undersize and will not have enough interference fit to properly secure the valve stem seals.

Cutter
http://www.silver-seal.com/product/SL1270/Valve-Guide-Spot-Facer-For-AirElectric-Drill.html

Pilot/Arbor
http://www.silver-seal.com/product/SL1270C/Pilot-for-Valve-Guide-Spot-Facer-38-Smooth-ID.html

Hope this helps

I've used cutters from both Isky and Comp Cams that cut the guide O.D. for a seal and shorten it up, there are many different sizes, and to cut the inner step down flush with the heads for dual springs. I shoot for .060 valve seal to valve keepers or retainers, which ever is the closes

yes, there are different size guide top and OD cutters.
.500, .530, .562 OD's and yes they cut down the diameter and top of the guide height at one time. I would suggest you use a .562 OD as this will leave the guide much stronger with a 3/8 stemed valve, guide wall thickness thicker. And as Road hazzard said you have to figure retainer to guide clearance with the valve seal. These cutters work with a standard 1/2 drill and doesn't require a machine to do it. Use a steel 6 ruler as a guide for getting the height some what consistant.

Regards, MLR426

OK, thanks Cab, roadhazard and MRL!

A spotcutter is what I'm looking for, have heard of them, just didn't know it applied here.

Not really concerned about going to a different size seal. Stock is fine as this won't be a daily driver ever.

Yeah, maybe I'll measure cut something to stop the arbor from plunging too deep and to keep the cut depth consistent. Basically, drop it down the valveguide to limit depth.

Thanks again!

There's also a 0.625" cutter that I've used on my lowbuck 318 heads, uses the stock type seals.

Bpought mine used on Ebay. It took 15 minutes from beginning to end.

R.