Vortec heads

[Stuart]

I have one more question. I do have 906 number heads so what significance is that and what's the difference from that of any other numbers. Do they have more hp or what?

 

[Pontiac455]

Another thing u have to watch out for with too much lift is the guides are too high. The retainer will bottom out hitting the guide.

 

[Stuart]

The engine is all stock so I don't believe there would be too much lift but good to know

 

[ssn696]

The 9060 heads are the more common castings. They are what you can still buy new from GM. If I recall correctly, this number head has less cracking issues than the earlier castings.

 

[Stuart]

The 9060 heads are the more common castings. They are what you can still buy new from GM. If I recall correctly, this number head has less cracking issues than the earlier castings.

Okay thank you. That's good to know considering those are the ones I have

 

[ssn696]

One more detail. The 93 Caprice came with a roller cam. Use the same (or same length) pushrods with your self-aligning stamped Vortec rockers. If reusing them, use some brake cleaner and flush all the old oil and junk out of them before reusing them. Make sure you use assembly lube, preferably moly, on the valve tips, rockers and pushrods when you put it all back together. You will also need Vortec-style intake gaskets, and different bolts (longer) on the eight intake bolts. Summit can provide you a bolt kit. I *think* they are 2-1/2", but see what the catalog says.
The one picture shows GM OEM gaskets with metal inserts that limit the 'crush', and the other picture shows the Fel-Pro universal ones with cutouts for both original and Vortec-style bolt patterns. Vortecs use two bolts at each corner of the manifold, none in the middle. And they go straight down rather than angled through the intake flange.

 

[Stuart]

This is why I love this site. You guys really know your stuff and help me out a lot. I've never done swaps like this so thank you for all the help! This is all great info and I will be sure to consider it all. Thanks so much again

 

[ssn696]

Others may disagree, but when I use the paper-style intake gaskets, I put a thin ring of RTV around the water passage hole (the big one at each end), both sides of the gasket. Try not let them move and slip out of place, smearing this seal. You can use the cork or rubber gaskets for each end of the intake, or just a thick (1/4") bead of RTV. Dry-fit the intake and gaskets first to get an idea of how much RTV to use. If you use the gaskets, put a dab of RTV under each end of the end gasket, then another dab, then set the intake-head gasket, tabs into the slots, then another dab, so they are sandwiched in RTV at the corner of the head-block interface - a common place to leak oil.

 

[Stuart]

Great! Thanks for the suggestion. The last thing I need is a leak

 

[ssn696]

Found these. I got a set of fraternal twins from Summit. Boy head, girl head. But the boys helped with the bolts.