i can normally get my hands on good vortec heads, if i go that route what kind of gains should i expect, what modifacations will i have to make to my tpi set up?, and overall is this a good direction to go with the vast world of aftermarket head choices? ......the main choice for vortecs is bc of cost normally my buddy at the dealership gets good sets and passes them on to me for around $200-$300 port and polish them up? what do you guys think?

 

Are these the later model Vortec heads with the four straight up intake bolts per head?

You will need the aftermarket Vortec TPI intake from Scoggin Dickey. (They sell it cheaper than Edelbrock does.) Your stock TPI intake will not fit. Also keep in mind they do not have the EGR passages, so your EGR valve will not work, and you'll get an SES light when you drive on the highway. You can buy their EGR adapter kit which makes the EGR work like the TPI Corvettes do.

And if you want to put in an aftermarket cam, I recommend the Manley 22410-16 springs and 23652-16 retainers. These will bolt right onto the head and allow you to run up to .550" lift camshafts with no trouble. A ZZ4 camshaft works great with these heads and a TPI setup.

 

One of the factory LT1 cam grinds would work well too. The Vortec heads are VERY similar in design to the LT1 heads - actually, the Vortecs were based on the LT1 heads.