NORT

I have an '84 Z-28 and have an older model 350 in it. I need to do something with my heads:the guides are bad and I seem to have some valve leakage. I have been told that the LT-1 vortec heads are a good way to go, they are very reasonable in price and i've been told can bring me up to 30 to 50hp. I guess I need to know if all my other stuff will work, the set that I'm looking at are already drilled and taped to accept my intake. What I need to know is if my pushrods,headers, & rocker arms will work, as well as do you know if they would be drilled and set up so my accessories-- alt.,power steering and yes even my A/C bracket-- will bolt up. I know that is a lot of stuff but I would apprecate some input. Thanks NORT

Ray87Z

They require self aligning rocker arms, you can pick some up for fairly cheap if you just go w/ stamped 1.5 stock style rockers. Try Jim Pace or Scoggin Dickey for those. I got mine for like $50-$75 if I remember correctly.

You also need centerbolt valve covers.

On another note, I would not buy the Vortecs that are pre-drilled for regular intakes. First off, there is not enough material for the threads, you'll have problems w/ them stripping. On top of that the intake ports will not line up w/ a standard intake. People keep overlooking that, you will lose almost all of the benefit of having the Vortecs if you use a regular intake.

You would be better off to get standard Vortecs and buy either a Performer, or Performer RPM to fit them from Edelbrock.

They have all the standard accessory bolt holes BTW. Everything on my 87 bolted up just fine.

BTW, they are L31 Vortec heads, not LT1. They share some intake and combustion chamber design w/ the LT1 heads, but they are not the same head. Just a minor point.

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Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray

[This message has been edited by Ray87Z (edited October 10, 2000).]

Vader

NORT,

Vortec heads come drilled and tapped for all accessories and sensors. Unfortunately, they require the use of a different intake manifold due to the modified bolt pattern (no bolts at the center ports) and higher port positions. Coolant passages are in the correct locations for Gen I blocks.

The heads flow very well right out of the box, and are equipped with 1.94/1.50 valves. They also have pressed rocker studs, so before bolting them on, I'd suggest a little pulling and tapping for screwed studs. It's also a good time to cut the spring seat diameters for larger springs if you ever intend to change the cam profile. Pushrod length is "standard" at 7.794 on flat tappet cammmed engines. The heads are designed for center-bolt rocker covers, but you can get perimeter adapter plates if you're really stuck on your original covers.

As an option, the GMPP "Fast-Burn" heads flow very well and are more friendly to install on an older engine. These use either the center-bolt or perimter-bolt rocker covers, and will accept the standard 12-hole intake manifolds or eight-hole Vortec manifolds. The valves are slightly larger at 2.00/1.55, and the heads come equipped with screwed studs. The balance of valve train parts are "standard" for the engine they are installed on, whether a flat- or roller-cam.

Neither of these heads has a provision for EGR gas through the intake manifold, but between the two I'd pick the Aluminum Fast-Burn for best performance as delivered. These are very similar to the World Sportsman II heads in design and performance, but have smaller chambers for additional compression.

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Later,
Vader
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"Make Me Bad"
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Ray87Z

The fast burns also have the raised/taller intake ports though, so a Vortec manifold is still best, standard intake would choke em as well w/o some decent port matching...

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray

[This message has been edited by Ray87Z (edited October 11, 2000).]