The heads I ran last year (ET ported 98 castings with stock valves) worked just fine, these picked up a solid 2mph in the 1/8 with less compression so I'm happy. Only regret is these heads arent legal for the NMCA 'steet race' class and I would have liked to run a couple of those events. 221cc max runner size and you 205s are 'legal.' Hard to be cheap and try to class race lol.

 

Good luck getting a head to fit those rules and work well as a LS1 head. I've wanted Dart to make the 205cc casting of theirs legal for that class for a while now.

Bret

 

AFR 205s are legal, they are listed. I assume the AFR 205s are less then 221cc CNC'd. Dart 205s are listed but those are SBC heads, not LS1

 

This is one of the best "threads" Ive seen In a looooong time thanks everyone just about changed my mind on quite a few things! Thanks to everyone!

 

I really don't think you can go wrong either way, AFR & Dart are both high quality heads. For my $$ though I'd go w/ the Darts.

 

I just wanna know how many freakin times we are gonna have to tell people that ADVERTISED flow numbers don't mean jack ****.. ADVERTISED numbers are just that.. ADVERTISED!!! Search for independant numbers from reputable shops like W2W, Thunder Racing, HPE, LME, etc. And why does TSP/PRC NEVER post exhaust flow numbers? Hmmm...

If you want to spend a grand on a set of ported stock castings then go ahead. That might be your cup of tea. But, when I think about "going fast" or "building a nice setup" there isn't anything "STOCK" left in the equation. When you buy a set of AFRs or Darts or ETP heads you are getting a quality AFTERMARKET head that has many many many different features that make it ALOT more efficient than a ported "stock" 5.7/5.3/6.0/ls6 head.. Yeah you can work on a ls6 head for hours and hours or slap it on a cnc machine and get flow numbers that are close to the AFRs or even higher numbers in some cases. But, how efficient are the heads? What size is the intake runner on the ls6 head? I'd bet my *** that its ALOT bigger than the AFR 205 and/or the AFR 225.. What kind of velocity/volume do the ported ls6 heads have? Thats why the AFR 205s have consistantly made good power.. They are far superior to any stock head in my opinion. Some stock heads might flow more, but you have to factor in all of the other quality features that put them ahead of the stock castings.

The AFR heads are tried and true. It has been proven time and time again in dyno testing and track testing. You truly do get what you pay for. A quality AFTERMARKET head full of nice features and top of the line parts with the customer service to back it all up.. I learned the hard way when I bought my heads. I have since seen the light and realized that if you want quality then you have to be willing to pay for it..

p.s. ADVERTISED FLOW NUMBERS ARE TOTAL BULLSHIT!!

 

Originally posted by KP

"Biggest mistake is simply assuming just because you use an AFR, ET or any other 'top shelf' cylinder head you are guaranteed big power without the proper supporting pieces, thats a bigger mistake then choosing the wrong head over others. There is a big enough market where no one should be complaining, since supply is always a probelm it appears that all aftermarket LSx heads are selling well."

"FWIW I picked the Darts because they were cheap, I am cheap - I'll admit it. But I also have had good luck with Dart products over the years and just assumed they wouldnt turn out a piece of junk. I paid for them just like anyone else (actually I paid more) and they suit my needs just fine. If I had an unlimited budget I would have a set of AFR 225s or ETs on the car, but then again if I had an unlimited budget I would have a 402 and twin T67s instead of a 346 and a D1SC also."

I think Tony is referring to the average guy that buys a HC package running an N\A setup. This is really the majority here, not many people have the luxury of running a HC with supporting mods and a D1SC.

 

AFR, in my opinion, are the best aftermarket heads available. Also, in my opinion, they need to change up the way they process orders, or plan their production. Don't get me wrong, I believe the best is worth waiting for, but if AFR gets any slower at delivering, they'll start going backwards. Sometimes I think they mine their own bauxite before they cast your heads. Out of all the aftermarket parts producers I've dealt with, they are BY FAR, the slowest.

Other than that, you couldn't possibly own a better set of heads...........if you don't die of natural causes before they arrive.

 

get AFR 205s!

 

225cc is for larger displacement engines and wont be any more benefitial then 205cc heads with 346 CI.As a matter of fact you may lose some low end torque.

 

Well put. AFR is pure technolagy. When the made the 205Mongoose heads they started form a clean sheet of paper and designed everything from scratch and basing their design off trial and error until they came up with a great set of heads.

The 205's made 530HP with a mild cam running thrue a flowmaster muffler with an otherwise stock block.

 

225's are a bit much for stock CI applications.

If you go with the 205cc Mongoose heads, have 'em milled around .011", or so, and go with .040" Cometic head gaskets. I'd assume you'd also be doing a cam swap, and new pushrods? If so, a Comp cam somewhere around 222*/228*, .581/.588, 114 LSA should match up pretty well with the heads. You'll make insane mid-to-hi range power.

The LS6 intake will help, but if you can afford it down the road, get a FAST 90/90. An aftermarket oil pump (Melling, etc.) and an LS2 timing chain wouldn't hurt, either.

Of course, all of these parts will be worth about as much as a 3-foot high pile of ****, without a GOOD tune.

 

You woud be amazed but there are ported LS6 heads out there that are smaller than a AFR 225cc and out flow them. That's even on a 3.90" bore. Then again they cost more than a AFR 225cc so, back to the discussion.

FWIW I'm not of the opinion that a 225cc runner is too much for a stock cube application. Even on a street car.

Bret

 

Ported LSx-series heads, for being OEM components, are not at all a bad choice for a performance build. Hell, they flow great numbers right off the showroom floor...when F-Bods we're still being made.

That said, I've ridden in, raced against, and watched too many AFR-equipped cars to doubt them. AFR advertises flow numbers like everyone else does, but when I go to the track, their heads aren't on flow benches, they're on engines, and in my limited experience, I see them on more engines than any other brand, and, most importantly, they deliver the goods. I'm a member of 2 local car clubs, so I get my fair share of time at the track, cruise nights, and "on the street". Around here, AFR rules. That's not to say that they are superior to any other brand...all I'm saying, is that locally, AFR FAR outnumbers any other brand of aftermarket head.

These posts about brands (and I don't care what it is...heads, headers, cams, cat-backs,....you name it) can be interesting, and it's nice to keep up with the latest tech, but, man, I don't know of a faster way to start a war than to say, "I think brand X is better than brand Y".

And when you think about it, who is really qualified to say so? The only headers you ever see me write about, are Kooks, and that's because they're the only headers I've ever installed. I cannot honestly say they are better or worse than any other brand, because I've never had any other brand on any of my cars. How many guys have had Kooks, Pacesetter, QTP, Dynatech, Hooker, Dynomax, SLP, or Stainless Works headers on the same car, to do a valid, real-world, comparison? It's the same thing with heads. Now, you can argue price, delivery time, and customer service, but that's in an entirely different universe than performance.

BTW, AFR's own literature recommends 205cc heads over the 225cc for stock CI engines.

 

I think the AFR's are great and I have admired them since they came out but they just aren't in the budget for most of us. I may run just a little slower than the AFR guys but I do have an extra grand in my pocket to spend on other mods.

 

Am I looking at this wrong? This link brings me to the PRC heads page, I add the Comp 918 spriings and CNC port, then x2 the number for a PAIR of heads (not one) and I get $2,299.98. That's certainly NOT $1,000 less than AFR's...

Russ

 

I'm pretty sure 'each' means pair, thats what I read a while back anyhow..