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I've been wanting to get a pair of heads for quite some time now and I can't decide whether to go Vortec or to try the Sportsman II from World Products, these of course of for a stock 350 that I just want a little more kick out of, only mods are intake and headers. My question is which ones will give me more power the Vortecs or the Sportsman II's both being 64cc.
Im comparing these two, summitracing part no.
NAL-12558060
WRL-011250-2
Thanks in advance!
i am going to go out on a limb here and guess the sportsman 2's. below is an exact quote from thier site about the heads. unless the vortecs have had a litte work done to them you probably wont get a 30 to 70 hp gain as with the sportsmans.
Continuously improved since its 1987 introduction, the Sportsman II is still the industry's most popular cast iron high performance head. Featuring RightCast® 200cc intake runners, Fast-Burn chambers and your choice of angled or straight plugs, they're good for 30-70 horsepower increases right out of the box. They are the aftermarket's only 50-state emissions legal cast iron high performance cylinder head (E.O. #D-343-1). You should also know that all World Products heads are precision CNC-machined, and indexed off the chambers to assure perfect alignment with the cylinders.
i'd go with the sportsman IIs and reccomend also stepping up the cam just a little bit to get the most out of your new parts.... you'll have to go with cam and lifters since the lifters you have have already worn to your cam
For the same price i'd probably go for the Dart iron eagle 180cc's. The sportsman 2's are getting a little bit outdated with the combustion chamber design they have nowadays and they only come in 200cc which is a little big for a mild 350.
If it's the '79 truck you are putting the heads on, I would use the Vortec heads. No smog legal cam will run good with the sportsman 2's, it will need something much bigger.
Judging by the dyno tests on ryanscarpage, the Vortecs will whip any of the OEM heads and also most of the aftermarket heads except AFR's and some twisted wedge heads. I agree with 69elko that the runners are too big on the Sportsman heads for a street-running 350. A rule of thumb for a street motor is half the cubic inches for runner volume, so the Vortecs would get the nod if it were me buying the parts. They're 64 cc chambers with 170 cc intake runners. I'd use a true flat-top piston, not the stock Chevy type with a depression in the middle and 4 valve reliefs, because you will not get a good squish with them. Chevy says the Vortecs work best with flat-tops. I'd buy the low-buck assembled heads (Chevy 12558060) and change out the springs and retainers to the Crane units under part number 10309-1. No machining required and good for valve lift of 0.575", about 0.125" better than the stock springs and retainers.
0.030"-over flat-tops will give you 10.4:1 with 0.040" gasket and zero deck. Use something like the Crower Hot Street Beast, part number 00903, grind number 278H, 112 LDA, 278*/284* advertised, 218*/226* @0.050" tappet lift, 0.462"/0.470" theoretical valve lift. Makes power from 2,000 to 5,700 with valve float at 6,200+. A 2,000 stall converter will put the icing on the cake.
Thanks for the replies guys, I was leaning more towards the Vortecs anyways. Ill look into those chevy heads / valve combination techinspector. :cool:
I would'nt even look at a 200 cc intake volume until you think you will hit 7,500 rpm's in a 383 or 7,800 in a 350.Quote:
Originally Posted by 79C10