Good luck with the Vortec heads.
It's difficult (expensive) to keep the EGR system when using Vortecs. You'll have to deal with either the hyperexpensive GM TBI-to-Vortec intake manifold, or the improper fitment of accessory struts and such with Vortec "carb" intake manifolds + a TBI adapter. You'll have to fabricate something for the bracket that holds the throttle, cruise, and transmission TV cables since the stock bracket is intended to use the angled intake manifold bolts and the Vortec manifold bolts are positioned differently.
In short, the Vortec heads are a pain in the ass with no good solution. Better to get the Summit aluminum "TBI" heads instead of Vortecs. Use the stock intake manifold, and ZERO fitment problems or fabricating.
www.summitracing.com/parts/sum-162108
Free Shipping - Summit Racing™ 62cc Aluminum Cylinder Heads for Small Chevy with qualifying orders of $109. Shop Cylinder Heads at Summit Racing.
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THIS cam?
www.summitracing.com/parts/sum-162108
Free Shipping - Summit Racing™ 62cc Aluminum Cylinder Heads for Small Chevy with qualifying orders of $109. Shop Cylinder Heads at Summit Racing.
www.summitracing.com
.454 lift with 1.5; means .4842 lift with 1.6 rockers. I don't think 1.6 rockers are inherently a problem. You'll need to verify that the valve springs will be stiff enough, and can accept the lift you're going to have--along with retainer-to-seal (or guide) clearance, etc.
These are self-aligning rockers...right? If you don't have self-aligning rockers, you have to get pushrod guideplates and hardened pushrods or the guideplates will scrape the stock, non-hardened pushrods and fill the oil with shavings. The way I remember Vortec heads is that they've got press-in studs, so guideplates are difficult without machinework and new rocker studs.
The bigger question is "why would you install a flat-tappet cam?" Your engine may have a block already set up for an OEM roller cam. OEM roller-cam parts are readily available in the Treasure Yards for little money. You'd end up with a better/more durable system with little chance of break-in problems.
If you INSIST on a flat-tappet cam,
make sure you pay extra to have it Nitrided.
No promises on what sort of tuning you'll have to do to make the computer happy with the new cam. That cam has an emissions approval for '87 and older carb'ed engines, but not TBI.