Vortec heads on 305 TBI? performance?
01-28-2003, 03:50 AM
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Vortec heads on 305 TBI? performance?
91 RS 305 TBI, T5 in California (Smog-sensitive state!)
I have a standing offer for a pair of used Vortec heads from a friend of mine.
These heads have the angled bolt-holes im told.
I also have an offer on some old 202 camelhumps.
Im really favoring Vortec since Ive heard so much about them. My real question is if I decide to put the vortecs on, i know i need to replace my intake. What intake should I shoot for that will offer nice hp gain that is compatible with those Vortec heads. Will i need to replace my valves/springs and how do i go about understanding sizes and so forth. What kind of hp gain should I expect from this swap. BTW, my engine is bone-stock, never touched the top-end or bottom-end, just wires, plugs, air cleaner assembly.
What is mandatory to replace, and what can I salvage?
oh, and im convinced 200 bucks is a good price for either set of heads, which is what i was quoted.
Both sets have been crack-checked and are in good shape. The vortec fella is a buddy and has a lot of engine building experience as in he knows how to put one back together, but not so much technical knowledge. I am in a good position to have it all installed right, but i just need information i can count on.
Thanks for catering to my ignorance.
I have a standing offer for a pair of used Vortec heads from a friend of mine.
These heads have the angled bolt-holes im told.
I also have an offer on some old 202 camelhumps.
Im really favoring Vortec since Ive heard so much about them. My real question is if I decide to put the vortecs on, i know i need to replace my intake. What intake should I shoot for that will offer nice hp gain that is compatible with those Vortec heads. Will i need to replace my valves/springs and how do i go about understanding sizes and so forth. What kind of hp gain should I expect from this swap. BTW, my engine is bone-stock, never touched the top-end or bottom-end, just wires, plugs, air cleaner assembly.
What is mandatory to replace, and what can I salvage?
oh, and im convinced 200 bucks is a good price for either set of heads, which is what i was quoted.
Both sets have been crack-checked and are in good shape. The vortec fella is a buddy and has a lot of engine building experience as in he knows how to put one back together, but not so much technical knowledge. I am in a good position to have it all installed right, but i just need information i can count on.
Thanks for catering to my ignorance.
01-28-2003, 09:27 AM
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The Vortec heads have a special intake pattern that you will need to match to a Vortec intake. Vortec heads don't have EGR passages either, so the EGR will have to be plumbed from the exhaust manifolds/headers in order for you to be legal.
Out of those two heads, I would choose the Vortecs.
Out of those two heads, I would choose the Vortecs.
01-28-2003, 10:26 AM
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I'm going to have to disagree here.
IMO the double hump fuelie heads are far superior to the Vortecs. Plus, intakes, valvecovers, etc. are cheaper and easier to find used(or new most of the time).
On a side note, if the Vortecs are drilled for the old style manifold, then a Performer RPM manifold has slightly raised ports which match decently well to the Vortecs. They can be picked up for $50 - $100. Port matching is necessary to get good flow obviously. My frankenmouse was good enough without any grinding to push my 3420 lb lead sled to a 14.2 at 98 mph with that combo.
Other things to note is that the old style holes are drilled into water jackets so you have to seal the intake bolt threads.
IMO the double hump fuelie heads are far superior to the Vortecs. Plus, intakes, valvecovers, etc. are cheaper and easier to find used(or new most of the time).
On a side note, if the Vortecs are drilled for the old style manifold, then a Performer RPM manifold has slightly raised ports which match decently well to the Vortecs. They can be picked up for $50 - $100. Port matching is necessary to get good flow obviously. My frankenmouse was good enough without any grinding to push my 3420 lb lead sled to a 14.2 at 98 mph with that combo.
Other things to note is that the old style holes are drilled into water jackets so you have to seal the intake bolt threads.
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