vortec heads on a carb motor?

[superwade57]

I just got a pair of vortec 5.7 heads from a 98 truck will they do me any good on a carbed motor? Does any one know what the specs are. How much lift can i run on my cam? and I assume they make an intake to use on these heads with a Carb mount can some one throw some advice suggestions my way?
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[thesickc10]

Originally Posted by superwade57

I just got a pair of vortec 5.7 heads from a 98 truck will they do me any good on a carbed motor? Does any one know what the specs are. How much lift can i run on my cam? and I assume they make an intake to use on these heads with a Carb mount can some one throw some advice suggestions my way?
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ill just built a motor using these heads for my buddies car. i dont know the specs but with a mild cam the motor made a ton of power. they use a special intake that only uses 8 bolts 2 in each corner. edelbrock sells aluminum ones but if you want a cast one you have to get it off of a mercruiser boat engine.

[BigBlocksRule]

Max lift in stock form is somewhere around .475, it varies quite a bit.
There are plenty of intakes made for 'em with carbs. You may want to look at the Performer RPM, not the air gap. The Performer RPM has provision to plumb hot water under the carb pad to help with cold weather warm up, etc. They respond well to a bit of bowl cleanup, especially on the exhaust short turn.

[Pop's C-10]

Yes they will do d*(m good on a carbed motor..185cc intake port..65c exhaugst..450"lift cam max..you have to get a vortec only intake

GM sells a crate motor that makes 330 & will move a OSB carbed truck well..
http://www.jegs.com/i/GM-Performance...ductId=1231165

[superwade57]

You guys rock! All kinds of good news and suggestions in like 10 minutes! That's why I love this site! I've got an old. Wolverine blue racer can specs are 510 lift and 310 degree. Duration. That's Prolly a LOL much for stock springs but will the valves be big enough to do that cam justice?
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[joe1982]

Originally Posted by Pop's C-10

Yes they will do d*(m good on a carbed motor..185cc intake port..65c exhaugst..450"lift cam max..you have to get a vortec only intake

GM sells a crate motor that makes 330 & will move a OSB carbed truck well..
http://www.jegs.com/i/GM-Performance...ductId=1231165

THats my engine

[superwade57]

I'm pulling those cam specs out of my head so I'm pretty sure that's what thy but can 2x check if they seem out of wack could be 210 degree tho
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[BigBlocksRule]

It's not the springs, the guides are too tall, the retainers will hit 'em. You can take the heads to a machine shop and have the guides cut down, a lot of folks have the spring pockets opened up so you can use bigger springs.

[79beater]

The tool to machine them down is only about $60 from summit and is easy to do with a 1/2 drill. It uses a pilot and cutter that follows the valve guide. Just measure the clearance to the seal and spring retainer. Make sure it is .060 more than the lift.

[superwade57]

great info guys. That being said does any one know what the springs will handle?
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[BigBlocksRule]

^ yeah, but I always like for my machinist to set up my springs, he charges less than the cost of the tool to cut the guides down. I also get him to machine the top of the guides for positive seals and install Viton seals when he sets the heads up. I make sure I've done all the bowl work, etc. before I take 'em to him.
BTW, the factory valve job on Vortec heads SUCKS!!!

[superwade57]

Bigblocks- can I talk you into elaborating on what specifically sucks?
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[BigBlocksRule]

Yeah, it's very rough, not conducive to good flow at all. A good performance 3-angle valve job will pick up at least 10cfm and a few ponies. The factory valve job is almost square, performance is a lot more rounded/radiused.

[79beater]

The tool that cuts the guides down also cuts the boss to accept the positive seals. It does it all at the same time. Quick and easy. The springs are extreamly weak. Get the springs specified for the cam in the diameter of the stock springs. Thats what I did.

[jojoman]

so what cam do you paln on using i plan on doing the same for now but just keep them just stock i guess but dont know what cam any suggestions

[Maxzillian]

Ditto on the 330 hp engine. It's a fine runner and with my 2wd truck and 2.73 gears I've bested it out at 18 mpg so far (12-14 mpg daily driving 20 miles a day). When I bought my truck I had plans on swapping in a 4 cylinder diesel until I ran the engine a bit.

[Norwood]

Originally Posted by Maxzillian

Ditto on the 330 hp engine. It's a fine runner and with my 2wd truck and 2.73 gears I've bested it out at 18 mpg so far (12-14 mpg daily driving 20 miles a day). When I bought my truck I had plans on swapping in a 4 cylinder diesel until I ran the engine a bit.

I aint never heard of a 4 cylinder diesel, that must be something from the army or mexico. That would probably run like a dog with no power at all. Instead I would go with a camaro motor from the 90s but take off the fuel injection crap and run a holley 750 dbl pumper and some gears like 3.73. THAT will give you some power!

[veinbar]

I have have built the following engine, which is very close to what you're describing:
1. 350 ci w/ mech fuel pump hole and 1 piece rear main seal.
2. "906" vortec heads w/ 3 angle valve job.
3. Performer (not RPM) Aluminum Intake (spread bore)
4. Reman'ed Q-Jet (jets and needs unknown)
5. The "summit cam" - http://www.summitracing.com/parts/SUM-1102/ - Duration 262/272, Lift .420/.442

With dual 2.25" exhaust, and open element air filter this was a great daily driver. Very smooth, great torque band, and as economic as these engines can get. I enjoy this set up, and the HP gains over stock heads is impressive. If I had gone with a more aggressive cam I would have selected the RPM intake.

[jrcaprai]

The definitive Vortec Head Guide

http://www.nastyz28.com/forum/showthread.php?t=56505