My friend wants to add some more power to his car next year and we are trying ot figure out what is the better idea. He originally wanted a HSR intake to go on his already ported stock heads. But he is now thinking about just getting some aluminum Vette L98 heads so he can still use the HSR. But I've read alot of good things about the Vortecs and though that those with the Scoggin Dickey Vortec base may be another option. What is the better option for the most HP for the $$? He is on a tigth budget so we are looking at all an ANY way to go with it for the most HP per $$. Any suggestions would be great!

 

Well, if hes on a budget then the HSR/Al. l98 heads win hands down. Hell, even from a performance standpoint they win. The complete HSR and fuel rails goes for approx. $500. Vette heads can be picked up for around $300 used.

The SDPC base ALONE is $400, figure another 5-600 for the vortecs, and youll still need the rest of the TPI like runners and a plenum to go with it.

Granted, the vortecs flow better than the vette heads, but the TPI will totally ruin it.

 

What heads does he have? Are the ported heads on his car cast L98 heads? The cast iron heads flow just as good as the aluminum and (hopefully) better since they have been ported. I really don't think there will be any advantage to going vortech either, since the L98 heads should flow as good or better than the vortechs also. If he wants more speed he should get some good aftermarket heads, cast iron is fine, and HSR. He could try the HSR on his heads and find out if the reason he isn't running like he wants could be because of his TPI intake and not his heads. I just ported my cast iron L98 heads and they outflow vortechs, fastburns, and are very close to out of the box AFR 190s (within10cfm).
If you want budget performance try the intake and see.

Good luck,
Charlie

 

If he already has ported L98 cast iron heads installed, which are outflowing stock aluminum L98 heads, I would ditch the aluminum heads idea and just buy the stealthram.

If he wants more emphasis on torque the vortec heads with the sdpc baseplate tpi make an awesome combo.

 

Ya, maybe he should just try the intake then, not sure how much port work was done on the heads. Won't the Vette heads raise the compression too? He has an SLP cam, not the largest one they had. I'd have to look up the specs on it.

 

The aluminum heads are worth 1 point in compression generally, but any performance advantage really is negated if the don't flow better. 1 point is generally worth only 4% of power (10hp on a 400hp engine). I will take flow over compression any day.

Good luck,
Charlie

 

I'll never understand why Ford people come to this CHEVROLET site. I'll never understand why you guys talk to the enemy.

 

Stock for stock, the aluminum L98's WILL flow better than Irons stock. If you dont believe me, Ill go out in the garage and take pictures stock vs. stock. The aluminum L98's are almost perfectly matched to the stock intake gasket, as where the irons are waaaay off. Another benefit of the aluminum heads are higher compression 58cc chamers opposed to the 64cc irons, and the ability to run more timing due to less detonation.

How much port work is done to his current iron heads?

 

I have only seen the exhaust ports, they look pretty good. Mostly looks like a good cleanup, all nice and smooth. I never saw them off the car though...

 

Good point, the aluminum "D" exhaust ports flow EXCEPTIONALLY well, better than any stock casting, and with some slight work, will outflow any other heavily worked stock casting.

 

I just figured that he did the iron headed porting for practice, then once he got the aluminum L98 heads that they would get ported too. . .

RBob.

 

I am also looking into this intake/head swap situation. I have stock cast iron l98 heads however, with no porting. I was considering the vortecs with the new intake base, and new slp runners. However, if the stealthram will give me better performance for $600 as compared to $1300 for the other setup, im all for it. Also, if i decide on the stealth ram, what heads will work with it?

 

The stealth ram will work with any conventional 23* SBC head.

 

There's nothing wrong with a "good" ported set of vette heads on a 350. Once you start getting more cubes though the small runners just won't support enough rpm for a big cube'd engine, that is if you like your engine to run up top. I really don't believe in hand porting yourself unless you take them to a flow bench in between the head mods. and after you're done w/ the porting. The vortecs will flow as good as any non-cnc'd ported vette heads on the intake side, which say a lot IMO. They really only need to be tweaked on the exhaust. These heads really make great power when ported, more than the vette heads. Out of the two combos on a 350 the SR/l98 heads will make more hp, but the other combo will make more tq. They'd probably run close at the track (et not mph) everything else being the same. I've actually got a set of ported vettes laying around that are practically new, w/ all the good upgrades since I paid about $900 for them from GM about 3yrs ago. That's before I knew anything about perf. cars. I just knew that Johnny Ling. used them.

 

camarojoe: Where did you get the heads ported? I am looking to get a set of aluminum L98 heads ported, but I want to make sure I get the best possible job done. Price is an object, but I believe in value for performance.

Thanks

 

A friend of mine who's ported a few sets of heads ported my vette heads. He used a head porting article from the net as a reference. If you want to get the heads ported I know Total engine airflow could get the job done, but it'll cost around $800. But they're a top notch shop. You get what you pay for and I'm sure the extra price is worth the flow #'s.

 

Flow test: www.dcpnet.org/stuff/Headstest_4.jpg
Stock Vortecs wayyy outflow Al L98s on the intake side, and match/beat the exhaust side up to .400 lift only then starting to fall slightly behind. They should yield noticeably better power gains if everything else is equal on a mild street motor. Since the intakes won't be equal the comparison gets interesting. The power numbers I've seen when using the SDPC TPI intake have not been mindblowing though IMO.

In the end I would go with the Vortec/SDPC intake setup for most budget conscious setup ($425 Vortecs, $400 intake, port stock runners and upgrade them later), OR go the HSR route but spend a little more money (vs used AL L98s) and substitute something like a set of Trickflow heads or something similar...

 

I have a set of L98 alums that Im working on. With properly matched ports, 3 angle valve job, and some bowl work, Im sure that they will outflow stock vortecs. Im going to concentrate on the intake side of the head for the most part, as the exhaust is pretty well off. Ill be retaining the stock valves as well.

 

Intake is great, but if you can't get the air out almost as easily, then a lot of power is lost just trying to push that volume of air out of the exhaust port. Most novice engine builders (like myself) forget that getting the air out is just as important as getting the air in.

 

Well considering the exhaust flows better than the vortecs as cast, I dont think it will be a problem. Im going to work on the exh side, just concentrate more on the intake which needs it the most.

 

More important, actually. With a good flowing exhaust side it will help to draw air through the intake and scavenge the cylinders better.

 

camarojoe,

Shoot me an email at RDNK4RE@AOL.COM about those heads if you want to sell them.