Post pics of your valvetrain setup!

[Erik the Awful]

If you install aftermarket roller rockers, some Vortec valve covers have a narrower PCV box than the TBIs. I'm not sure if the change was between Vortecs and TBIs or in the middle of the Vortec run. You're already working on a Vortec, so you might be fine, but if you nab a junkyard valve cover, be sure and get a narrow one.

 

[Trenton]

If they're the same diameter as the valve and angle as the retainer then I don't see why not. Now to be clear does the + mean it increases installed height?

As far as I'm concerned, yeah it means it adds 0.050" to the spring install height.

 

[Trenton]

Photo 1. TFS Twisted Wedge Gen 1 cylinder head (top view) Yes, the rocker studs are NOT all in a line. 2.02/1.60 valves. Comp Pro-Magnum rocker arms (Intake rockers are special for the TW heads.) 1.6 ratio, 7/16 stud.
Not shown: OEM L31 roller cam 'n' lifters.
http://hbassociates.us/K1500_Twisted_Wedge_07.jpg

You must be registered for see images attach

That looks badass! Is there a benefit to the valve stems having a different angle like that?

Also, I love you signature.

 

[Schurkey]

That looks badass! Is there a benefit to the valve stems having a different angle like that?

http://hbassociates.us/Twisted_Wedge_G1_Instructions.pdf

They sold well enough to warrant an updated, "Gen 2" version, also with goofy valve angles, but not the same angles as the "Gen 1". Because of the relocated valves, the Gen 1 Twisted Wedge heads are the ONLY 2.02/1.60 heads that will clear the bore walls of a 305. (I'm using them on a 400 in my 'Camino, and on a 5.7L in the K1500.)

They're a very-OK street head. Not a "race" head. Port sizing and flow rates were better than OEM. They came pre-drilled for steam holes to fit 400 sbc. The chambers are just a bit wide for a 4" bore, but work great on the 4.120 bore of a 400. There were issues with valve guide wear on some heads, which I've heard is traceable to

1. Improper rocker arms on the intake valves. Trick Flow claimed that stock rocker arms were OK. I could not get an acceptable contact pattern with "regular" Pro-Magnum roller rocker arms. I contacted Comp Cams, they had four part numbers for "special" rockers specifically for these heads. (1.5 and 1.6 ratio, 3/8 and 7/16 stud size.)

2. Improper machining of the spring pockets, which--I guess--were not always 90 degrees to the valve guide.

The set on my K1500 were purchased used off of eBay. They were pretty beat-up when I got them--lots of corrosion in the water jacket. The valves, seats, and guides were OK, though. I back-cut the intake valves, lapped the valves to the seats, and had the castings pressure-tested, and planed for straightness.

Trick Flow discontinued the Gen 1 and the Gen 2 heads a LONG time ago. I bought my first set in the early 1990s. About a thousand dollars a pair--a low price at the time but this was before the friggin' Commies started supplying bottom-feeder auto parts. I've got a couple pair on vehicles, and one set still in the boxes.

Also, I love you signature.

Biological warfare is working out pretty well for the Communist Chinese. No country in the entire world has called them on it. Expect them to do this again.