Hey guys i'm building a 383 for my friends truck i bought a scat crank lt1 cam and all the berings and stuff i still need pistons but i want to figure out what heads to run before i buy them. Anyways what heads do you think will work better a set or stock vortecs or a set or world products iron s/r torquer heads??? He doesnt want a racecar just a nice daily driver that will pull a trailer once in a while. Thanks for any help.

 

Welcome to the world of TGO!

You can't beat the budget performance that factory vortec castings have to offer. They are a great head that will fit your needs. However, they come with addition expenses because you need a different intake manifold to use with these heads. Since your power levels are modest I would also consider a set of 350 TBI heads (193 casting) with port work. New evidence has shown that porting these heads can make decent power for motors similar to yours. Vortecs can be improved on the exhaust side with port work and 193's can be improved with port work on the intake side. You basically have to pick the lesser of two flaws. A viortec head should offer more potential performance than a 350 TBI head, but you can still make 400+ lb feet of the good stuff with those heads. Not to mention that you can get them for next to nothing out of a junk yard.

 

yeah the vortecs are great for the street, but if you really wanna make power go with the world products heads and have someone good port the hell out of em.... more meat for modification than the vortecs.

 

If your going to get a set of cheap stock heads to port, L98's would be the best. They have a simpler intake port then the 193's and will likely flow better after a DIY porting.

As far as being thin, all the lightweight stock head castings seem to suffer from that. My vortecs where so thin between the ports and the bowls that I swore I could see through them. My tbi and junk smog heads where the same way.

 

dimented24x7 and I disagree on this point as discussed elsewhere in another thread. The DIY porting numbers suggest that both the 083 and 193 heads can achieve the similar intake flow numbers, and that the 193 heads will provide better exh flow numbers. The 193 heads will still have the swirl ramp, albeit smoothed, so the 193s should have a quicker burn and require less ignition advance and have no difficulty on 87 octane. Those are both useful features for a truck application. I'd choose the head based on availability & low cost, because both can be made to work very well.

L31 heads weigh 41 lbs each, while the 193 castings weigh 46 lbs each -- both stripped of hardware per PaulD's measurements. It looks like the factory tried to thin the L31 heads where possible, and I can't imagine that the swirl ramps weigh more than a pound per ramp, even here on Thirdgen. FWIW.

 

i was told today that the dart s/s heads might be something to conisder as well what do you think of theses heads are the better than the world product heads there about the same price.

 

I think you can meet you goal without breaking the bank. Some simple head work and the right cam will wake up that motor like you wouldn't believe.

 

Id just go with the Vortecs if you want a bolt and go motor. Youll need a new manifold, anyway since the stock tbi one is less then desirable on a 383. As long as it isnt subject to cali style emmissions/visual youll be ok emmissions wise with a plumbed up EGR. IF your not doing any tuning on the ecm side (not recommended) then youll have to have the egr.

Back to the tuning, you might be able to get away without it since the 383 + LT1 cam may have a powerband close to the stock motor, but you really should get a prom programmer and do the tuning yourself. Whatever you do, no aftermarket chips, they wont help anything.

 

Yep, I'm with Dimented. Slap some Vortecs on because you should replace the manifold anyways. A 383 with Vortecs would be a great, torquey motor.

 

you know, one option that's often overlooked are aluminum zz4 heads. they have 58cc chambers, so there's no drop in compression, you can pick them up pretty cheap on ebay, and a simple 200.00 pocket port makes them flow almost as well as vortecs.

i have a set i bought last year for a grand, but they've had some SERIOUS flow work done to them; they outflow vortecs by a pretty decent margin below .550 lift. even at that price, i figured it was actually cheaper than vortecs would have been after i upgraded the springs and cut the seats, had them milled to keep the compression up, and bought that expensive gmpp intake. and by the way, milling those heads as much as they'll need for compression will cause some major valvetrain geometry headaches.

people love to talk about that 305 tbi vortec project gmhtp did last year, but they did some MAJOR porting and polishing on those vortec heads. look at the before and after flow numbers. there's no way you'd come close to those numbers with stock heads.

car craft did an article on building a cheap 500 hp 350 this month. they used the new 49cc chamber dart iron eagle heads. i got pretty excited when i read it. can you imagine, swappin on a head that would actually RAISE compression? won't work, though. i talked to the tech support guys who told me almost every aftermarket head spaces the valves further apart, which makes them unusable on a small bore like a 305, 307 or 283. you'd have to cut valve reliefs in the block and you'd still have shrouding issues.

: (

 

read the above post. unfortunately, they won't work. valves won't clear the block

 

The ZZ4 aluminum heads are the Corvette L98 heads (113 casting suffix). GM did revise the casting recently, so the newer ones do flow better than ones from 10+ years ago. There is also two versions of them, one with 1.94/1.50 valves and the other with 2.00/1.55 valves (basically putting them to the specification level of Vizard's best porting efforts on the 113 castings. All of this info is on the GMPP web site, after some digging. HTH.

 

The new large port vortecs look pretty sweet. But I think there a little over $1000 for an assembled pair.