|09-04-2008 08:29 PM|
|HAYWIRE||The Vortec head design is great its the rest of the vortec engine package that sucks....the poppet style injectors, the hard to program black box computer, the distributer (dizzy),and the leak prone intake gaskets are all reasons not to transplant this engine into anything else. I own a 98 excab 2wd and cannot get 20mpg with it. My vortec headed 350 in my 79 gets 22 to 23mpg consistantly with the same gear and trans ratios and it has a 650 holley double pumper....and its 3 seconds faster in the quarter. Keep it simple put a carb on it with vortec heads or if you have your heart set on transplanting something better go with the 4.8, 5.3 or 6.0L engine combinations....Im sure they have their issues too but atleast they are current and manufacturers are still building hop up parts for them.....Sorry for the rant but thats my 2 cents.....for what its worth lol....Lorne|
|09-04-2008 06:15 PM|
The RHS Vortec head, which is based off the OEM casting, is better than the OEM head. I've flowed them vs OEM and if you get the pro torker model, with the multi radius seats, and 2.02-1.6 valves, it out flows the stockers by a good margin.
Also, they are twice as thick on the deck surface and have more meat around the seats, reducing the problem of the crack prone factory vortec head. If you want to run your factory manifold, it will fit, but you will need to match the manifold to the height of the runners on the Vortec heads, and do a port match job. These heads are cast in Australia, and RHS is part of the Comp Cams group, so they are good quality.
It will run better with a dedicated Vortec intake, so if I were you, I would plan on using a Vortec style manifold. There are heads floating around out there claiming to be Vortec heads when they really are not.
In order to be a vortec head, it has to be patterned after the GM design. The name sells, so be careful of what you are buying.
Otherwise, use junkyard models, but get them magnafluxed, and make sure the bone yard will take them back if they are busted. Look closely at the center bolt holes on the deck surface of the head, and look closely at the exhaust seats. I've fixed alot of these cracks, but you need the right equipment to do it.
|09-04-2008 05:06 PM|
|stroker_SS||Instead of machining the vortecs for more lift, you can simply install a set of ls1 (beehive) valve springs and run to something like .525 lift. The whole set is pretty expensive though( like $250 for springs, retainers, keepers etc) but when you subtract the cost of machine work(and the waiting for the machine shop to get it finished,which can be a serious annoyance if you ask me), and a new set of regular springs, keepers etc. that can handle .525 lift. It seems allthemore worth it.|
|09-04-2008 05:03 PM|
|Red neck blazer||
Thanks guys. I have tme to think bout the cam fer my motor and then figure out what i will do. But i think i will have to have a set when it comes tme. Thanks agian
|09-04-2008 04:22 PM|
"aftermarket vortec style heads"
"Aftermarket" refers to manufacturers other than OEM, such as the aforementioned Jimmy-Crack-Corn and Ah-So heads which are junk in my opinion.
I'm talking about using genuine GM Vortec heads. You can buy them new across the counter at any Chevy dealer or you can harvest them from a boneyard motor, '96 to '99 Chevy truck with 350 Vortec motor. Look for a sawtooth design on the end of the heads and pull the valve covers to verify casting numbers 12558062 or 10239906. If you get heads from a boneyard, get the rocker arms (special rail rockers for use with Vortec heads) and valve covers (center bolt design) with them. Take them to a machine shop and have them magnafluxed for cracks. Unaltered Vortecs will have a valve lift limit of 0.450" due to clearance between the underside of the retainer and the top of the valve seal and will have to be disassembled and the clearance increased if you plan to run valve lift over 0.450". Or, you can purchase heads which have been modified for more lift. Or, you can get a camshaft with more duration and lift-limited to 0.450" from any of the cam grinders. Scoggin-Dickey sells heads which have been modified for 0.525" lift under part number SD8060A2, assembled with valves, springs, seals and retainers.
New 12558060 heads.....
New 12558060 (SD8060A2) heads modified for more lift.....
Please thoroughly read this page from Gilbert Chevrolet.....
|09-04-2008 03:40 PM|
|Red neck blazer||
So if im reading right the after market vortec style heads or finding a doner truck with the motor and trans i want is the way to go. Not just finding head and puting in a whole computer and that junk. IF you mean it another way let me kno. I want good pull power and mpg that is standable. Cause when i get done with my truck it wont be drove much and plenty of time to just work on it.
|09-04-2008 03:18 PM|
125508060 is a part number of the original 1996 & up production Vortec. It can be made from either a 10239906 or a 12558062 casting. The difference between them is that the 906 uses hard seat inserts and the 062 uses induction hardening. Scoggin Dicky among others sell a modified version for cam lifts over .45 inch at the valve. This head requires a specific intake that has raised runners and the Vortec unique bolt pattern, GMPP and Edlebrock supply units for a carb. Keep in mind this head does not have a provision for exhaust heat to the intake and if you need EGR it has to be externally plumbed.
GMPP has also released part numbers 25534421 and 25534431. These are Vortec style heads with heavier casting thicknesses and larger 2.02 and 1.55 inch valves, they accept higher lifts without modification and feature a 180 cc intake for the 421 and 206 cc intake for the 431. These are complete ready to run heads, they are also available under a different P/N as machined but bare. The original Vortec "060" heads all use 1.94/1.50 valves with a 165-170 cc intake port. These use the standard Chevy bolt pattern for the intake but the intake still needs to be a raised runner type.
Putting a complete injected Vortec into a non injected, non computerized vehicle is a big project, not impossible, but a challenging effort. You need the computer, wire harness, sensors, injection pump and lots of detail parts. Additionally, the computer needs information from the transmission and about the vehicle that older vehicles can't supply without modification to the transmission, installation of A to D converters or replacement with a Vortec era transmission. There will be problems with instruments such as the speedo, requiring a converter, or outright replacement to an electronic unit. Like I said not impossible but an extensive and technically challenging swap.
Unfortunately, the Vortec injection isn't that great, any type of performance work and for general reliability these systems are usually back dated with port injection parts from older TPI systems.
|09-04-2008 03:01 PM|
You can get heads that are called "Vortec" and will work with a conventional manifold, but they won't be genuine GM Vortec heads. They'll be made by Jimmy-Crack-Corn Induction Systems or Ah-So Industries or whatever and in my opinion, are a waste of money. None of the knock-offs have shown me that they flow anywhere near the original 12558060 GM heads. Having to use a dedicated manifold is a small price to pay in my opinion.
Knowing nothing at all about EFI and the new electronic systems and unwilling to learn at my age, re-wiring for a computer-based system sounds to me like a nightmare. I guess if I were going to do it, I'd buy a donor vehicle and install all the wiring from it to my ride, ripping out all the original wiring. I'm told there are companies who specialize in wiring systems to do it, but they won't be getting any of my money.
|09-04-2008 01:57 PM|
|Red neck blazer||
I have a 79 4 bolt 355. And was wanting to stroke and bore a little more. But can i get a set of vortic heads that my holley 4bb in take will fit. Or if i go vortic then do i have to buy a diff 4bb intake. Or is all this just wishful thinking and ill have to go fuel injection with the vortic. And how hard would it be to wire up a vortic in my 86 blazer. And what is some of the other things that would have to be changed in the truck to make it work? Thanks guy i kno that yall will know the best way to go. Thank agian