Vortec Heads, need help

[J Thomas]

I'm trying to plan a rebuild for my 1992 K1500 with a 350. Im.not wanting to build a monster, just something with a bit more heart. So here is what I've come up with:

Vortec Heads
Summit Racing TBI intake to Vortec Heads
Stock Exhaust manifolds

I know I need to be looking towards a good cam and an upgraded TBI.

I've found a few Vortec Heads on craigslist, but honestly, I'm lacking knowledge on whether or not they're good or bad. My brother in law runs his own car repair shop and he'll be doing my rebuild, not me.

Getting back to the heads, can y'all educate me on what I should look for, steer clear from, what's a decent price and whether or not they should be assembled.

I'm looking for real knowledge and know how. I'm trying to avoid buying a junk set. Please guys help so I don't make a bad buy.

Thanks is advance!

 

[Ironhead]

I have been told that Vortec heads are prone to cracking after they have been used for a few years. Not sure if this a problem that is more severe with the Vortec heads, but my feeling is that if the heads are used, it would be very smart to have them crack tested before completing the deal. If the seller will not have them tested, you have to wonder why.

 

[J Thomas]

Is it better to buy new?

 

[Ironhead]

Well, I have an older GMC truck with a 350 and 4 barrel, and a 98 5.7 Vortec, and the vortec starts easier, idles more smoothly, accelerates much quicker, and gets way better fuel mileage. I know that the fuel injection has a lot to do with all that, but most folks reckon the heads are a major improvement.

New would be a better choice, if the budget allows.

 

[Biggershaft96]

Get #906 heads off a 3/4 ton or 1 ton if you can. They hand inconel valve seats. If you buy new from gm/gmpp you will get #062 heads which still arnt bad, the inconel just lasts longer and provides a better seal. Other than that, they perform the same. I think you can get up to a .500 lift cam before running into clearance issues but youll need different valve springs to go much over stock. Best bet would be to get a cam kit as apposed to just the cam itself.

 

[cool_as_crap]

Check this out, i've watched damn near every one of this guy's vids

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"Stock vortec heads are prone to crack"

He makes a good point: you can buy new complete 350 vortec aftermarket heads for like $600 - $800, which have an improved design over stock.

 

[Oldguy]

A couple of years ago I rebuilt a '98 engine completely. It was .030 overbore with stock crank and fully machined, decked to provide .030 inches of squish and cammed. Heads were stock Vortecs. Within a year I had gone thru three teardowns with head related problems. Biggest problem was the rocker studs pulling out, even after going up to 7/16" diameter screwed in studs. One set of stock heads was rebuilt, cc'd and had new valves put in only to have to be discarded because the machine shop broke the head trying to pull out one of the rocker studs. After throwing so much good money after bad I decided to go to aftermarket heads from Dart. I got the Iron Eagle heads and have been one happy camper ever since. As an aside I found the cam overworked the LS lifters and it never ran real good until I switched in some Johnson HY-Lifts. This was an expensive education and took two years to get it all sorted out. Once that happened this truck has been a sweetheart, very light on it's feet, responsive and gets good fuel mileage. (With a light touch on the go pedal)

 

[boredandstroked]

If your pulling screw in studs out of the heads you have insane valvespring pressures, because thats not normal.

 

[TylerZ281500]

Get #906 heads off a 3/4 ton or 1 ton if you can. They hand inconel valve seats. If you buy new from gm/gmpp you will get #062 heads which still arnt bad, the inconel just lasts longer and provides a better seal. Other than that, they perform the same. I think you can get up to a .500 lift cam before running into clearance issues but youll need different valve springs to go much over stock. Best bet would be to get a cam kit as apposed to just the cam itself.

the data to prove that isnt available, both have been found to have them, they are entirely the same head through and through

vortecs crack, i wouldnt be buying used ones for any more than 50 bucks, then send them out to be cleaned and sonic checked. its a 50 50 shot if they are good or bad, but still the best flwoing GM heads to date. your other option if your up for porting is take a dremel heavily at your 193's they flow decent but you wont make power up top as high as vortecs or other heads. third option completely aftermarket, protopline vortecs or similar or grab a set of world torquers, iron eagles etc.

to pull out 7/16s screw in studs is impossible actually, you can break them or break the head even with stupid high spring pressure, at that point youd bend push rods before anything.

as far as tuneable cam, stock lt1, mtc1, k1102, and similar will function well

 

[J Thomas]

Do you have any recommendations on a good set of heads for a DD that you feel are better than vortecs?