Aftermarket Product ReviewProvide questions and answers about aftermarket parts for the Third Generation F-Body.
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Theres a considerable amount of posts on this board concerning these two pro-topline heads.
This is the only post I found with any mention of an objective flow test. Link
::edit- pic wont attach- its the 6th post down on the link::
These numbers look pretty high and almost a 'too good to be true' number when compared to Chevy High Performance's data. It should be noted that the Stock vortec flow data is printed twice in their mag. The first time (that i saw) was in the much read GM Goodwrench Quest Part 4
Both of these flow tests were done on a 'westech' bench. But the discrepancy bewteen these two posted flow rates is mind blowing. One has a horrible I/E relationship, one good. One has much worse intake flow numbers, one better.
My question is: Though the flow numbers of Pro Topline heads look great and have seemingly amazing I/E relationship, How am I to pick between these two considering how arbitrary these flow numbers seem to be - even with the examples provided by CHP??
And then, how do you quantify BSFC and the other variables that work for power vis a vis cylinder heads. I need good below 5000 rpm torque with an efficient chamber to move around my car.
How's a guy to pick between the two and make the right choice??
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Last edited by 9c1Caprice; 01-07-2004 at 09:41 PM.
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You can't go wrong with Vortec heads for a good torquey street engine. Face it even Edelbrock copied them and then compare their now BEST head against them.
__________________ 1989 Pontiac GTA Nighthawk, 389 CID, 10.3:1, Eagle Stroker Crank, Eagle 6 inch rods, KB Dish Pistons, CC XR269-HR-12, Crane 1.5 Golds, Fully Internally Balanced, Ported Exhaust and 1.6 Exhaust Valve Vortec Heads, Headman Ceramic Coated Shorties port matched to Vortec Heads, Ported SLP's, SDPC Base, Ported Plenum, 52mm TB, 30 lb. Injectors, Streetdampr, Crane Hi-6S, Underdrive Crank Pulley, Be-Cool Radiator and dual fans, 450 HP 500 TQ. Vigilante 2800 stall Converter and TCI Steetfighter Trans. Spohn Torque arm w/safety loop, LCA's, Panhard rod and LCA relocation brackets, Aluminum driveshaft, Flowmaster 3" catback, Flowmaster muffler, High Flow 3" Cat, Custom Y-Pipe.
Thanks for the reply. You make a good point. Everyone is copying them and making good builds with them. Untill I see something more solid and concrete about these pro toplines, I'm going with the tried and true, proven factory pieces.
Pro-Topline heads are usually more a race oriented than a Vortec's. For max power with supporting mods the Pro-Topline will be the best iron head. However, the Vortec's are excellent in their own right as mentioned above.
Originally posted by Arctic White 91 RS Pro-Topline heads are usually more a race oriented than a Vortec's. For max power with supporting mods the Pro-Topline will be the best iron head. However, the Vortec's are excellent in their own right as mentioned above.
Race oriented- maybe thats it.
There are some problems with the stock vortec heads, such as the combustion chambers need to be cut on the intake port to reduce valve shrouding or to increase swirl and the exhaust port needs a little work.
Of course some of these modifications come at a price.
Were these modifications made to run with tradeoffs (there almost always are tradeoffs) to make the heads run at higher rpm's?
Vortec heads- good for apps under 5000 rpms and Pro's at a higher rpm band?
Or maybe youre talking about the casting's durability and screw-in studs good for higher horsepower/RPM applications
Depending on the rest of your intake system and cam is what determines the heads. The ported L98's have the best E/I ratio, but used they are about $500, so the price knocks them out.
For the cash, I'd pick the vortecs and have them ported in the chambers and exhaust, with better springs and the back cut valves.
Originally posted by 89gta383 For the cash, I'd pick the vortecs and have them ported in the chambers and exhaust, with better springs and the back cut valves.
And how much more money does it cost for all of that?
Originally posted by Arctic White 91 RS Pro-Topline heads are usually more a race oriented than a Vortec's. For max power with supporting mods the Pro-Topline will be the best iron head. However, the Vortec's are excellent in their own right as mentioned above.
I have a set of both. The Pro-Toplines are more performance oriented. The factory Vortecs were originally intended for trucks and that's where my stock factory Vortecs reside...on a 400 SBC built for big torque in my Suburban. The Pro-Toplines pick up where the factory Vortecs stopped. I've found their improvement in flow is not much better. Where they shine is in the improved design. They already have screw-in studs (stockers are pressed), the spring pockets are already enlarged and the guides cut down (both necessary modifications for lifts over .480 on the stockers), improved water jackets for better cooling around the chamber, and much thicker deck surfaces which will accomodate a 45 cc chamber (stockers are pushing it at 58cc). If you intention is to put Vortecs on a milder motor with less than .480 cam lift, go with the factories. If your intentions are bigger, ProToplines...no question. They were built for the performance enthusiast.
Thanks for the replies. Im reading alot about how the Pro-Toplines are better suited for high horsepower applications due to their improvements related to strength, i.e. thicker castings, screw in studs. However, I'm still looking around for a comparative flow and/or dyno comparison.
I see why people dismiss the heads as 'truck' heads. Weak stock springs, screw in stucs, etc. However, their Iron lt1 ports (flow better than aluminum lt1's) move air great up to .500 and have great mid lift flow numbers. Their contributions to good VE numbers and BSFC are well documented. This has been hashed out on here before, but its too bad there is no good a/b comparison between the two heads.
There is some discussion revolving around flow, but I guess there is no hard info on the subject. Ive been looking everywhere for some flow data. Furthermore, I really appreciate all of the discussion here on these two heads.
I'm running the pro topline vortecs. I can't really compare them to gm vortecs or e-tech heads as I have never run those, but I am very pleased with the pro toplines. I have been interested as well in the flow numbers. What I like about the protoplines is that there was no machining needed for my cams lift (.510 w/ 1.5's) I'm pretty sure they are capable of at least .550" lift.
I'm putting together a +.040 350 for my roomates s-10 and we're using the Topline Vortecs. We went w/ them because of the improvements over the GM vortec's, plus I was really impressed w/ Topline's casting quality w/ my 200cc aluminums. He had them flowed and they were pretty well right on Pro's #'s, and where they were different they surpassed the #'s on Pro topline's website. I think they're an excellent head. Cost $420 delivered to my door, bare. Can't beat that.
...now to gasket match them and dropped this polished Crosswind RPM intake on top w/ that 535/555 hyd roller cam..
i've been very impressed with my lightly modded factory vortec heads.. they've gotten me into the 11's with a well over 3000lb car, and poor gearing.
As far as modding to the heads i had the bowls blended, valve job, and a slight mill to them, using stock vavles.. including the price of the heads, machine work, all the hardware, and installation, with gaskets cost me 850 bucks.
I had no need for screw in studs. i'm running a comp XE 274 cam.. under .500 lift.. no super duper springs. so the stock studs are good for the time being.
one day i'll dig out the flow sheet again. was the bare heads, peak intake flow was 233 i belive. which is within a very little bit of what they did pre bowl work.. but all the below peak numbers significantly improved.
E/i ration at .500 is 72 or 74% i belive.. it stays in that range through out.
Originally posted by 89gta383 Depending on the rest of your intake system and cam is what determines the heads. The ported L98's have the best E/I ratio, but used they are about $500, so the price knocks them out.
For the cash, I'd pick the vortecs and have them ported in the chambers and exhaust, with better springs and the back cut valves.
Ive been doing alot of reading on vortecs lately. Pretty set on getting them i thought. but are you saying the stock l98 heads (i have) will flow as good or better when ported? Still learning here. Not fully understanding
I've had stock 062 vortec's, the pro-topline vortecs, and a set of Edelbrock E-200 vortecs .
I've had all of them side by side on my workbench and compared them.
From best to worst:
E-200's-due mainly to bigger runner size, a better looking exhaust port, and weight reduction. More than enough to feed a 525 horse 383 (although they still needed a light cleaning with a sanding roll).
The pro-toplines come in second, they looked a hell of a lot better than the stock vortec's. Plus they come with alot of perks that you have to pay for in machining on the stock vortecs. Good to 525-550 lift depending on springs and whether you're running hydraulic lifter or roller lifter cam.
The stock vortecs are a nice budget head. If you're building a 350 or 327 with less than 480 lift cam they're great.
I intended on using my pro-toplines for my buildup but had the e-200's dumped in my lap so to speak. Otherwise I'd use them without hesitation. They are still for sale or possible trade parts I need.
