I am putting in a comp 268 nitro hp cam, with matching springs. I have had the heads machined and tapped for screw in studs these are the stock iron heads (and ported). I reused the factory retainers and now I have no closed pressure I can spin them...will comps retainers give me the 1.7 install hieght I need... or shims are needed

 

Use the right retainers. There are a number of reasons why.

You will probably have to shim the exhausts up about .090" - .100" more than the intakes, because their seats are cut deeper to accomodate the factory "rotators".

 

so the retainers are the problem.... and what other reasons, they look pretty heavy duty compared to other heads I have done...

 

Why mess around with old retainers? They will probably do the job but their cheap enough, you may as well get a new set and a bag of shims while your at it!

 

"Heavy", yes; "heavy duty", no.

They're made out of much softer metal.

Their "steps" aren't the same diameters or heights that the new springs require.

They have wear on them in various places from their former life; where the springs rubbed on them, and the keepers.

They may or may not be the same height, as far as where the spring surface ends up, in relation to the keepers. Which might have something to do with your installed height problem.

They may be taller on the bottom, such that they will smash into the top of the guides at less valve lift than ones that were designed for cams with more lift.

Get the right ones. Keepers too.

 

I think either way will work. You can shim it to get closed pressure, then measure to make sure you have clearance when open, or get .050" offset locks, and check your pressure and clearance that way.