Hey guys, i have finally decided to get rid of my junky 305 and build a 383!
Iv had a few people tell me several idea's and was wanting some input for you guys since you've been so helpful in the past. Some people said i should keep the heads of my 305 and race port them, some have said to find a set of 350 heads and call it good while others said to race port the 350 heads. I am just looking to make some power but still make it more for street. Just something to play with. Any insight on this would be nice! Also im looking at 10:1 compression max if anyone was needing to know Thanks!

 

I wouldn't waste time on the TBI heads, but I wouldn't accept just any old 350 heads, either. If you're looking for stock heads, then something from an LG4, L69, LB9, or L98 would do, just watch your compression ratio when you build the 383. Anything from the 70s almost certainly isn't worth looking at.

 

Oh thats not true there are plenty of good heads from the 70's It's just hard to find them because the dirt track guys eat um all up. 487X, 993, 441, 336X, etc. It's probably easier/cheaper however to buy a set of Dart iron eagle, or World's S/R torquers unless you have a machine shop similar to mine as you will spend a lot more in the long run with factory heads to get that level of performance, and in the case of the darts unless you are an experianced machinist just have the valve job done, and bolt them on. They will be more than enough for what you are looking for.

~Couch

 

Alright guys thanks that is all great info, but i am looking for more ideas on the subject so anyone please shed some light on it for me

 

what exactly is it you are looking for? There's not a whole lot to talk about this is kind of a dried up subject matter. There are tried, and true methods to this and pretty much everything there is to know has been said. Once you choose the heads the subject matter gets much deeper, but choosing the heads is all about how much money you have. As I said earlier aftermarket heads are the way to go unless you have your own machine shop. The last set of factory casting small block chevy heads I machined for a dirt car went for $1200 his rules said factory castings so i turned a set of 993 heads into little dirt slinging monsters. His heads are 1.94/1.50 heads it would have cost more to get them to 2.02/1.60. Dart iron eagle heads cost ~600 a pair then valves, springs, retainers, locks, seals all the parts you have to buy anyway, but you don't have to pull the studs thread the bosses change the guides, and exhaust seats for bigger valves. They flow better then some of the best ported stock heads out of the box, and they are already set up for 2.02/1.60 valves. See in the end you save a bunch of money just buying them new. You also don't have to fish through cores to find a good one, and you don't have to worry about machining history, cracks, rusted jackets, etc. If you have any questions about your Dart heads you can call dart and talk to the guy that made them. All the while saving money, making more power, and getting better fuel efficiancy, in a set of heads you can use over, and over again with no worries. You pull those heads out of the box slap hardware in them and go spank any factory head out there for 2-300 dollars less. Labor is the expensive part trust me I'm on the other side of the table.

~Couch

 

While 487X heads can be made to flow well, the old chambers can't be fixed. The design is inherently inferior. Do the same work to 487Xs, 081s, 906 / 062 s, and S/R Torquers, put them all on 383s at 10.0:1, adjusted with the depths of the piston dishes, and the 906 / 062 s will return the best numbers, with the 081s in second, the S/R Torquers in third, and the 487Xs dead last. 416s are NOT as good as 081s, they'd be about equal with the S/R Torquers.

 

no dought the 487X's are not the best high performance choice over all it doesn't mean it's not a good head. To do all the same work I would agree, but you can "fix" the old chambers (if i get what you are trying to say here) we do it all the time for hobby stock cars. Now you can't make it do what vortec's do no not even close, but they are a better pick than a lot of closed chamber heads, and they are still a heavy head. In the dirt racing hobby stock class they have to keep the 1.94/1.50 valve sizes so that automatically takes the SR torquers off the table for comparissons sake. They have to use factory open chamber heads. We are only allowed to cut a 360 degree cut with the guide as the center point. No hand work at all. We do our trademark killer valve job, mill the heads to 68 cc chambers, and off they go. We rarely loose a race we finish. The heads I mentioned are "heavy heads" and flow better than the older closed chamber heads with the same valves virgin, and we often take up to .050" off the deck surfface of the head to get the chambers down to size with not a single failure due to lack of deck thickness. Iron 487X's flow 205 at a half inch lift untouched, L-98 Aluminum heads sit pretty at 196 with 1.94/1.50 valves also untouched both flow those numberd into a 4 inch hole 28" H2O. Now it's fair to say there will be some good gains with the chamber knoked back a bit also giving room to tailor a good chamber shape. So your statement may hold true, but if any difference it would be marginal, and all we have here is speculation. Flow determines hp chamber design determines how much fuel you feed it to get there. Now thats out of the way I wasn't arguing that the 487 is the superior head for hp, but that it's a good head in general, and it's from the 70's. The issue I see with light heads is you can't do a lot of cutting anywhere without finding great limitations, and especially with vortec heads they crack far too often for my taste. When you consider the cost of a vortec head it sounds good at first, but when you consider that you could have to buy them over, and over again is it really worth 10-15 hp difference even possibly 20 over the S/R's. I'm not the guy to say really. I like the vortec heads well enough, but for dollar spent I'd buy Darts and be done with all of this. No matter what factory head you choose, or even factory look a like as in the S/R torquer any real attempt at making them perform in my opinion is like putting a dress, and lipstick on a donkey just kind of silly when you consider the cost and labor involved. Just my opinion. Yes they CAN make power, but you will spend more in the long run just getting them anywhere near "there". Dart Iron eagle 200cc heads flow 265 cfm out of the box @ .500" 4 inch bore 28" H2O just in case anyone wondered. So basically if you painstakingly port factory heads with the help of a flow bench and go as far as you can to the heads full potential I mean epoxy, bolt sleeves, shoot take them to weld tech, and have them cnc port them whatever you want to spend money on. I'll do a valve job, and assemble my Darts, and I'll beat the pants off the factory heads on the same motor. No port work, just as they are. So I come back to the logical conclusion that while we sit here arguing over what the best of the worst is/was the answer still lies in the aftermarket.

Atilla I don't at all mean to argue with you or insult you. If you and I were sitting in the same room we would have a lot to talk about, and have fun doing it I think. I'm sorry to hear that you have cancer.

~Couch

 

chambers aren't just how much fuel, but more importantly for the street, how much spark timing. More advance is necessary for best power with slow burn chambers from the 70s, but even so, more advance is more negative torque. The earlier the spark, the more the burn before the piston is done getting to top center, and the more burn, the more pressure.
In some racing, MPG is more critical than it is on the street, and in other racing. MPG matters none at all.
Now, I was implying that we cannot add quench pads to the 487X or S/R or 416 chambers to give them that Vortec shape that is proven superior. 081s have 1 of the 2 quench pads, so that's their main advantage over 416s: less negative torque.
For less money than Dart Iron Eagle 200 heads, which I've already shown still need porting, you can get the RHS Vortec heads that flow even better, and do so with 30 cc less intake port volume, making them a far superior head.

 

To respond to your Dart vs. RHS statement:

Never played with RHS vortec's, but I have a set of Dart 200's that move 320-330 cfm across a 2.080 valve into a 4 inch hole, at .500" lift, @28" of vacuum which would over air just about any small block chevy you could concieve of.


Separate thought:

As far as the chambers on the 487's we run them at 36 degrees solid timing, and have no problems. Yes the rules limit our fuel too. We run pump gas different octanes based on temp. in that class. I can't imagine wanting to run any more timing than that on a gas engine. We gave up on distributors with advance a long time ago waiting on timing in the low end is a waste of time. As far as starting it up at 36 degrees you just pump some gas in first.... sorry injection guys carry a squirt bottle. As with this method of timing you get plenty of low end power, and as timing naturally retards as with solid timing you actually pick up more torque in the high end too. While it's true you can't add quench area the difference made in just that area alone doesn't have a lot of affect on hp, it's more for creating a more efficiant chamber, and making for a more complete burn so you get more out of every drop of fuel you use. The right chamber shape can help induce much better flow which is key to hp. Head flow cfm is directly related to hp. In fact: hp=.257(intake cfm @ 28" of water)x number of cylinders, you have to account for the entire induction system flow, but flow = hp there is no arguing that point. Once again the chamber decides how much fuel you have to feed it to get there. Thats how you control the "out of control spark" you feed it more fuel to get the same egt's. Once again we split hairs over which of the worst possible head choices are the best. Thats ok though someone will learn from it. What we are talking about here is so minute it dosen't even really matter. The statement that was made that I was countering was "there are no good heads from the 70's" I couldn't let that by without saying anything.

~Couch

 

I was starting to warm up to you, but now you're comparing apples to oranges. First you're discussing 1.94"-valved heads, then you go jumping to heads with bigger valves.
Yes, I am good enough to get around 320 cfm from Iron Eagle 200s, but I'm very sure that noone else on TGO.org is that good at porting. They'd have to buy AFR heads. Or pay me.
These guys aren't limited to 1.94" valves, and the S/R Torquers are offered with 1.94" valves in 58, 67 and 76 cc chamber sizes.
Next, AFR's rule of thumb, which you quoted, has been proven to not be an absolute.
Running rich cannot solve spark knock. It'll just foul plugs, and eventually destroy the cylinder walls and the bearings.

 

No no you misunderstand what I am comparing. I only have experiance with 1.94 valved 487's so I can't speak for anything else. The dirt cars I was referenceing are limited to 1.94 valved heads not the guys on this thread. They are also not limited to "no porting rules" as we are with those particular heads. So I can't speak for a ported version. We were or so I thought discussing the best head choices availible for the small block chevrolet. So far what I understood is that the L98 heads were on the table for discussion, the 081's, 416's, and the statement was made "no heads from the 70's are any good". I countered with not all heads from the 70's are bad providing examples. Then I compared factory heads along with the vast amount of work you would have to do in order to get them to perform along side even the most basic, and lowest cost aftermarket cylinder heads availible. Enter the aftermarket alternative leaving the discussion of factory heads behind. I can only pull knowlege from my experiance. I have ported dart heads to move up to 330 cfm across a 2.08 valve. I have done a street set with very basic bowl work that would move 290 cfm across a 2.02 valve, and I have used SR torquers with 2.02 valves these being the three cases i brought up as being the ones I could think of that stood out in my mind for this thread. I wasn't aware World S/R's came with 1.94 valves as I would never consider buying aftermarket heads that come with 1.94 valves so if I even ever came across such a thing I wouldn't pay it any attention unless it was for a 305 bore being a completely different animal anyway for which I would make completely different considerations concerning head choices. I am also unfamiliar with RHS heads especially those you mentioned mainly becasue we need the port volume for the RPM's we spin our motors at (more explanation about that in a minute.) Considering the low cost, and how well each of these cases did I was using these examples to try to deter anyone from using ANY factory head at all and consider aftermarket heads as a financially wiser investment. Due to the fact that factory, and aftermarket heads can't be compared at any level of performance or quality. and As I continued to get dragged back into the factory heads discussion my post probably became scattered as my thoughts wondered between the two separate topics making it hard to read. As far as the factory heads I never once even eluded to the fact that I was trying to put 487's against Vortecs, darts, RHS, L98's I was simply trying to say that the statement that was made was arguably inaccurate. All of these options are availible for the SBC so if you are going to consider your options I suggest nothing more than consider everything you can, and pick the solution that fits your cause. Should someone come accross this thread searching for heads for a dirt car with similar rules to our hobby stock or Limited classes, then they would find that I have researched, and discovered that the best heads they are allowed to use being the 487's. They are not allowed to run L89 or anything even close in those classes. For a street car my Dart heads argument has merrit, and your vortec argument has merrit. As I stated before none of these heads should never see each other in competition as there would be no comparison between them(factory vs. aftermarket), and I never ment to lead the discussion in that direction at all forgive me for being hard to understand. It is often hard for me to project a clear thought to others as there is so much going through my mind as I am typing. I have ADHD so I can't stay focused on just one idea before a stray thought jumps in my head I'll try to be more clear next time.

Unfortunatly I don't live in a town where drag racing, and street intrests are consistant enough to keep a shop like ours alive. The way we make money down here in Houston is to research, and develop dirt car motors, as we have found the formulas that work for just about every class down here. I rarely dabble with anything you guys would consider "streetable" I play with motors that are for sprint car racing all the way down to hobby classes. Our hobby heads aren't enough for your "street" projects, and our race heads are far and beyond anything most here would ever need. The last sprint car motor we sold recently went for a total build cost of $37000 yes thats 37 grand there is not a sprint car motor in the country that cost more to build. We owe this enormous cost to the state of the art oiling system, and absolutly cutting edge kinsler injection system. That motor turns 9500-10,000 rpms all with every waking moment of it's life. It's a push start car so once it lights off it's get in line, hammer it on green. Requiring heads with at least 200cc runners (it's a short track we need torque to get off the corners). Only for freinds, and family do I build "street" stuff for, and most of you would consider our "street" stuff to be either outlandish, or simple and boring, as my dad just likes to drive his cars on cruises, so we usually just use stock castings with the usual hop up hardware, nothing fancy at all. We on occation get to build drag race motors, but they are like Pro Mod motors 3000 horse blown nitro/alky mix motors, or tall deck 472 Ford strokers on rediculous amounts of nitrous. Put it this way we don't build a drag motor that doesn't require us to o-ring the deck of the block.

I know that fuel management is no way to control spark knock, but it's what we have to work with. It's not usually much of a change: a metering rod size difference or so can usually clean up the pre-ignition if there is any (limited to two barrel, or quadrajet carb.). As I said we build these heads on a motor with flat top 4 relief pistons, and a cam with max lift of .450, and some tracks have a 15" vacuum at 750 rpm rule. Not a lot of leway. The combination that put our cars as top 10 in the nation is our trademark valve job on 487 heads. We run solid timing at 36 degrees. We don't have issues with killing spark plugs, or motors for that matter. In dirt racing your doing good to get a motor to last a season in a half just because of the stresses involved anyway. Spark plugs are the least of our worries. We usually just have to hone the blocks, and because we have to use factory cranks, and oil control is the most difficult, and expensive challange to these motors we usually have to replace the crank and several rods when we rebuild these motors. The bore is rarely hurt at all. Thats my experience with 487 heads, thats why I stand firm behind them as being a "good" head. Not better than anything else that has been discussed, but excellant for what purpose we need them for. Not to further drag this post on, but the old chambers now obsolete by comparison, are what made this motor famous, to dismiss it all together is something I can't do. They were making power, awesome power in NASCAR, and the like with these heads, and chamber designs long before most of us knew what cylinder heads were. These heads do this currently every saturday night all over the country, and will continue too for many years to come. We have indeed come a long way, but that doesn't mean there is no "good" heads that arren't modern thats all the point I was making. In their house they are the best choice. Against the pro's they don't stand a chance. Hopefully this clears things up a bit.

~Couch