Guest jwelch Posted November 26, 2001 Share Posted November 26, 2001 Greetings, Has anyone tried the Vortec Heads on an older SBC (early 70's)? I saw an article that said these would decrease emissions and add approx. 40 HP to the engine. I find this hard to believe due to the fact that they are cast iron and are about $500.00 for a brand new pair(cheap). Some GM dealers are claiming these outperform aftermarket AL heads costing up to 3 times more. Just want to know if they are worth buying. It looks good on paper but I would like to hear some experiences. Thanks Quote Link to comment Share on other sites More sharing options...
Guest Thurem Posted November 26, 2001 Share Posted November 26, 2001 Check out all the magazines, ie. CHP and HRM. There are tons of articles about these heads. one article used 21cc D-dish pistons, zero deckheight and a comp cam XE268 cam for 390 horsepower on (get this) 87 octane. Static compression was 8.75. Me am doing the same thing, just slightly higher compression with 18 cc D-dishpistons, and polished chambers + bowlporting. You will need to get a Vortec specific intake manifold though, or one of the big partshouses offers these heads drilled for standard intakes. Thure Quote Link to comment Share on other sites More sharing options...
Tim240z Posted November 26, 2001 Share Posted November 26, 2001 I am using these on a 69 350 which I rebuilt for my cheyenne 20. Love them. Tim Quote Link to comment Share on other sites More sharing options...
Tim240z Posted November 26, 2001 Share Posted November 26, 2001 Ross C: quote: 2) be aware of their overall lift limits/springs etc and be sure to package your cam/springs etc Keep in mind that for a 'few bucks more' you can get the heads from GM with upgraded valve train that can handle higher lift cams. Tim Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted November 26, 2001 Share Posted November 26, 2001 "Keep in mind that for a 'few bucks more' you can get the heads from GM with upgraded valve train that can handle higher lift cams." Yup, guide bases/spring seat machined down/opened up/offset keepers etc....I just wanted to point out their various stages have limits typically a bit lower than the $1k aftermarket heads. These limits may not affect most builds as they still allow a fine cam, just wanted to raise the question if someone might want 550/600 lift etc out of them. what lift is the GM package allowing now? Their's more than a few 400hp+ vortec topend packages running around. Quote Link to comment Share on other sites More sharing options...
Mike C Posted November 27, 2001 Share Posted November 27, 2001 Gotta love modern combustion chambers The Vortecs are a great head, especially for the price. Only drawbacks (and they are minor) is with fewer intake bolts, there propensity to leak is higher than conventional setup. (Also, I wouldn't go with the redrilled heads for an older intake as you lose some of the benefits of the tall narrow intake ports) Also, the self-aligning rocker arms. With that out of the way, for a mild ~400hp street motor, they are a heck of a deal. Especially if you don't already have an intake. You can get a complete kit with rockers, bolts, gaskets, heads and an intake for less than $800 from Jim Pace and/or Scoggin Dickey. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 27, 2001 Share Posted November 27, 2001 two things.......... a local shop quoted me $50 to redrill the heads to take the older intakes and you can make a monster head by buying them bare and spending the money to make them a 2.02/1.6 valve...I did not think you could fit that big a valve in there but the friend that "claimed" he had that done also claimed that that in the flow bench they outflowed AFR heads. Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted November 27, 2001 Share Posted November 27, 2001 "a local shop quoted me $50 to redrill the heads to take the older intakes" if you use an 'old bolt pattern/port' intake you lose the gains of the vortecs runner design as was chimed in above, misalignment might seem slight, but it's enough to knock out some nice power just sitting their that makes Lt1's work so fine with mild cams. "valve in there but the friend that "claimed" he had that done also claimed that that in the flow bench they outflowed AFR heads" the smaller street AFR heads (can't recall numbers, was a couple years ago now) were relatively easy to outflow below .450/.500 lift where vortec's do very well. My RPM's outflowed a set of 2.06/1.60 AFR's I'd picked up, tested in a respectable bench to bench comparison, and promptly resold. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 27, 2001 Share Posted November 27, 2001 Hey JWelch. I have read a few articles on these heads and they do outperform a bunch of other heads costing a lot more!!! Double-bump and aluminum heads dont flow the same.Figure out the compression you want in the end then you can figure out the cc,s of the head and type of piston. You will need a specific intake manifold for vortec heads but then your set. ENJOY Quote Link to comment Share on other sites More sharing options...
Guest super280z Posted November 27, 2001 Share Posted November 27, 2001 would decrease emissions and add approx. 40 HP to the engine. I find this hard to believe due to the fact that they are cast iron and are about $500.00 for a brand new pair(cheap). if you're looking to spend around this neighborhood, take a look at the pro action iron lightnings. there's a guy out in Ca that sold me a set a while back he was asking like 530 to my door. just dont over do it though. these are rumored to flow over what there rated at. dont over look a set of heads just because there iron. ooh and BTW, these are old style SBC so none of the vortec BS to go with them. hope this helps. Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted November 27, 2001 Share Posted November 27, 2001 " I find this hard to believe due to the fact that they are cast iron and are about $500.00 for a brand new pair(cheap). " they work as others have stated, GM's made tons of them, v. similar to Lt1 alum. head. Main points to watch are 1) use a vortec intake, matching with an oldstyle intake knocks out many of the gains 2) be aware of their overall lift limits/springs etc and be sure to package your cam/springs etc they outflow the ported (lazy on the exhaust) vette L98(ZZ4) alum. heads and quite a few others Quote Link to comment Share on other sites More sharing options...
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