Can I use z-28 style valve springs(rated up to .550 lift) in stock heads with "pressed" in studs?. My current cam is small .462/.469. I always heard stock springs were good up to about .470 lift so I want to try better springs and roller tip rockers.

valve springs usually have a recommeded assembled height, do you have the necessary equipment to check this?

No I do not.

Originally posted by 75c10:
Can I use z-28 style valve springs(rated up to .550 lift) in stock heads with "pressed" in studs?. My current cam is small .462/.469. I always heard stock springs were good up to about .470 lift so I want to try better springs and roller tip rockers. =
The Z28 type springs that are rated to .550 normally set up at a higher than stock height & are slightly longer & usually have a higher rate.
You will need a either longer valve, higher retainer or taller set of locks or have teh heads cut & you will need to measure the installed height as mentioned above.
The measuring is not a big deal, you can do it with something as simple as a ruler with reasonable accuracy.
A piece of wire also works real well. You just assemble the retainer & locks with no spring & cut the wire the height you need & use it as a gauge between the underside of the retainer where the spring sits & the head or shims on the head.
Of course the right equipment like a height mike or snap gauge makes life a lot easier & more accurate & they are not that expensive :D

I don't like more than about 250-275 with pressed in studs. I would either pin them or have screw-in ones installed.

Mike,

Aren't the stock, Z-28 (-142) springs actually good to about .510" since they were ran on the -140 solid cams??

And ditto pinning studs with 1/8" x 1" long roll pins..

pdq67

Paul,
They have replacement Z28 "type" springs that are longer & will handle more lift.
These are not the standard Z28 spring.
There are a number of them out there now up to .600 but the installed height is 1.800-1.850 & some that are pretty expensive super clean chrome silicone "drop in" stuff for classes that require a stock type spring.
Comp has one but I don't remember the number

I know Mike,

I got a .600", (Z-28 type), spring, retainer and keeper kit from Midwest Motorsports for $55 plus S&H.

Elgin's PN RV1943X is supposedly good to .600".

Elgin's Z-28 spring, PN RV943X, is supposedly good to .550" but I personally wouldn't run her much over .500", but jmho is all...

pdq67

Originally posted by pdq67:
I know Mike,

I got a .600", (Z-28 type), spring, retainer and keeper kit from Midwest Motorsports for $55 plus S&H.

Elgin's PN RV1943X is supposedly good to .600".

Elgin's Z-28 spring, PN RV943X, is supposedly good to .550" but I personally wouldn't run her much over .500", but jmho is all...

pdq67 =
You are correct, I never use the 943's over .500" ;)
BTW, The Elgin spring is a Poineer RV943X

Gotcha!!

pdq67