Icepack212

Hey all, I just got a cheap set of used Vortec heads for my mostly stock 88 GTA. I am not very knowledgeable in heads and would like some personal opinions on how to get them installed right with the most power I can manage without any extreme work.

The heads are: Vortec 1.84"/1.5" with 58cc combustion chamber.

The head casting is 12558059 (after looking the number online I found out that they are from a 97 truck. That is all I could find out. I picked them up for a mere $180.00 and they come with valves and studs.

My stock GTA motor could obvously use more power and I knew the reputation of Vortec heads cannot be underestimated.

Can anyone tell me how much I can bore these over and if I could install these myself? If anyone knows any other areas where I might look at to get more info on Vortec heads please let me know, so far I've come up empty handed.

Thanks so much

billyhoss

iTrader: (1)

i think the vortec heads that u wanted are cast #`s 906 and 062, u may have vortec heads there but from a 305 tbi truck which are not the same as the other 2 #`s i listed, either way votec heds have a different bolt pattern then what u got now, instead of the 12 intake bolts they have 8, and a taller intake runner so u will have to get the right intake to match them, i have herd u can get the intake u have right now to work with them but it would need some work to get it to bolt up. but might not be worth it with the taller runners on the heads and the shorter ones on the org tpi intake, just my option though, i just put a set of heads on my 91 and got the intake to match them, not really hard to do , just go slow and make sure to mark where everything came from and torque everything back to org specs and u should be ok

Icepack212

Thx for the help, do you agree with me though that these heads are better than the stock cast iron L98 heads on my car?

Abubaca

iTrader: (3)

I think just about ANY heads are better, but you have to evaluate a effort/result comparo. I doubt it'd be worth much to do heads alone, and if you do heads, cam, exhaust, intake and some tuning, then you're still gonna be wishin' you had better heads.

Fast355

iTrader: (2)

The 305 vortec heads that I have seen (Read the CFI not TBI engines) are practically identical to the 350 ones. They flow very similarly and have a 58cc chamber. More flow and more compression=more power.

Ray87Z

Without some flow numbers in hand (I haven't seen any and some quick searching didn't turn any up online...) I woudn't want to spend any money/time fixing up the 305 Vortec heads, when they may be noticeably inferior.

I think I'd try to sell them to someone else who specifically wants the small valve head and get yourself some standard 350 Vortecs to start with... Then all you'd need is some slight/cheap tweaking to allow for more lift/better valvesprings and you'd be good to go....

billyhoss

iTrader: (1)

yes i agree they are very close to what u have on there now so really not worth the effort to change over to them since u need the other intake to match or get urs done to match them, i would go for the 350 vortec`s with the casting ending in 906 or 062, thats what i have and love them,

Icepack212

Thanks for the input all, from the sound of it I'll probably not get much of a power gain for the $180 I spent on the heads.....I guess I"ll sell em to someone who wants em.....unless someone tells me otherwise?

Fast355

iTrader: (2)

You have to consider that the 305 vortec makes 230 net hp with a cam that is milder than the 230 hp TPI 305. It is also doing it with the truck style intake, restrictive cast iorn manifolds, and a single catalytic converter. The 255 net hp 350 vortec uses the same cam, the same intake, and dual cats. The 305 vortec heads will give you a power gain, more than you are thinking. They are nearly the same damn head as the 350. They use the same chamber shape as the 601 which is a fast burn head design. The have the vortecs 8 bolt intake pattern, the raised ports, etc. The only 2 differences are the chambers and the intake valve size. I have installed them on a 400 before. That 400 ran better than it ever did with any smog era head.

Icepack212

Fast355: Man you just made me change my mind. Like I said I did not want to dump money into the car with a cam, intake and other stuff. If I did, i'd be buying a set of $3000 heads! I think I'm going to use these heads after all, considering the L98 motor has much potential and that these heads are superior to the stock cast iron heads.

I am just wondering, can I get these heads ported for more power?

Fast355

iTrader: (2)

Then if you want more power down the road, edelbrock makes a set of E-tec heads. You will need a new intake for the vortecs though. If it were me I would look for a ramjet intake (only if you don't have smog). Other than that SDC has the lower intake for TPI to vortec heads but they cost around $300.00. Maybe pick one up used off ebay.

Icepack212

besides getting a new intake, how much more can I maximize on the performance of this head? I was thinking about getting a new cam, but something that is not too expensive. As before can I port these heads or do anything more to them (besides getting them cleaned) to get more out of them?



PS I am in the Army and the time to do all this is not that available, thus I am sticking to keeping this car as a nice badass street rod that would tear a r!cer's *** off once in a while. Nothing too spectacular like a 13.00 1/4 mile....that I am saving towards a time when I have more bucks and more time! (possibly an LS1 based f-body in a few years)

kdrolt

The 305 Vortec head info, casting number, and flow numbers (after some porting) are posted on TGO. I think IHI may have been the owner, and I posted a URL for the data (305 L30 head vs 350 L31 head, BOTH Vortec).

EDIT. Here's some useful reading:

https://www.thirdgen.org/techbb2/sho...ght=Vortec+305

http://img.villagephotos.com/p/2004-...cflowsheet.jpg

https://www.thirdgen.org/techbb2/sho...ight=L69+heads

Icepack212

Ahh damn, them articles pretty much make me think that I made a mistake and wasted $180 on these heads for nothing. Man, if I get a better intake than my stock 350 intake, it seems that it would not be worth installing these heads. Maybe I outa sell them on ebay or to somone on these boards and save some $$ for 350 votecs?

Toomanyhobbys

Check out Scoggins Dickey for information. If you install a cam with a lift anymore than .460 or .480 (memory) you will need to add heavier duty valve springs. In addition to the new intake manifold you will also need a set of self aligning rockers. They will increase your compression. So depending on how tired the motor it might start eating some oil.

Ray87Z

Going by those flow numbers, with 2.02/1.6 valves already installed, they're near worthless without alot of porting...

The stock iron 350 TPI heads you've got should flow around 200cfm intake, 150 exhaust stock with the smaller valves (higher velocity) if I'm remembering correctly. Looks like a big step backwards IMO if you're not going to port them to get some decent flow...

Unload em on Ebay, I'm sure somebody will want them for a small cubic inch small block buildup or something. You can't be the only guy that will jump on them at the sight of the word "Vortec" either... Then see if you can't score some actual standard Vortecs for a decent price...

kdrolt

The stock unported iron heads (083 casting suffix) flow around 180/120 cfm intake/exh; only the most-recent revision of the 113 alum L98 head flows that well, box stock.

The iron ones flow 200+/150+ only after mild porting, and much better with a lot more effort. See (long) summary in this thread appprox 2/3rd down into the thread under my username. Links to each head flow data are included within. HTH.

Ray87Z

TPIS puts them at 196/140 @.500 w/ the standard flowbench setup (slightly higher at .600). Several sets of the numbers you posted from this board are questionable, the lowest being numbers extrapolated from a flowbench testing at 11" instead of 28 so I'm not sure they're particularly accurate... I believe the numbers F-bird posted are those straight from TPIS for the 083s, not his own testing... The numbers they've posted in some of their publications for various other GM factory heads have been right in line with most other published numbers available...

kdrolt

A. Source? I searched for TPIS flow #s on heads but only found the collection of TPIS flow #s on TPI runners/plenum etc. I searched several ways btw, and I couldn't find anything on head flow -- just intake stuff.

B. The 140 cfm number on the exhaust makes me question whether they were aluminum heads (113 casting, Vette L98 version).



I'm just the messenger -- the work was almost entirely done by TGO members, with a handful of other sources (magazine + Vizard)... so you are questioning their work, not mine. Yes there is a spread, but I'd rather see the spread than just one single number from one single test. Be specific, which ones are questionable?

It was also my impression that if you test at 11", and then extrapolate to 28", you get much higher flow figures after the extrapolation. The reason is that the extrapolation doesn't account for the extra turbulence and the extra viscous loss at higher test speeds (at larger vacuum) -- so the extrapolation overestimates the airflow. Yet you are suggesting the opposite: that testing at 11" and extrapolating to 28" gives the lower numbers.... and therefore underestimates the airflow. So that's a problem -- your criticism doesn't follow.

Which ones were tested at 11" ? Be specific and maybe I can get more detail. At some point that post will go into a sticky because it really doesn't belong buried deep in a thread so I'd prefer to take care of any issues now.



He's still here -- it's easy enough to ask him. He never mentioned that (otherwise I would have stated it specifically).

I haven't seen them. Are they in the TPIS TPI Insider's book (I don't own it)? I saw nothing on TPIS website that was helpful.

Icepack212

Alright, well from the reading of all the posts, it seems these heads would not be worth the time on my L98......should I bother looking at a set of heads that came on the Corvette with the L98 motor? How much better are they compared to the GTA L98 heads?

kdrolt

IMO you have choices that give you different hp gains but each has different costs. SOME of these are:

Vortec 062 or 906 heads (L31 350 5.7 versions): $500 new + $200 intake manifold. Demonstrated perf gains in many tests and by many owners.

Aftermkt alum heads (AFR for example, $1000+ new). Very expensive, best you can buy IMO. Flow better than the Vortecs, but not hugely better especially on the street.

GMPP alum 113 heads (alum L98). Dunno what they cost new but probably $700+. Use intake of your choice. Don't flow as well as either of the above, but definitely better than any stock iron (except for the L31).

Then there are the used versions of the above; cost and condition vary.

Or you can port factory iron heads, per some of the numbers shown in the thread I linked above. You can get airflow on-par with any of the above, for much less cost BUT a lot more DIY. Read the threads on each of the porting exercises and you'll see what's involved. Some people choose to spend, others choose to DIY. Both can work well.

Any way you do this, you will need ECM work to fully use ANY of the above head swaps... unless you have a MAF -- and even then you might need a small amount of tuning with the MAF. I had a MAF on my 94 LT1 copcar, so it retuned itself to slight mods, but I don't know if the Fcar MAF systems respond the same way. So don't dismiss the tuning issue. HTH.

Icepack212

Kdrolt: Thanks very much for your input. I believe my best bang for the buck at this time is to stick with Vortec 350 heads and perhaps get them ported. The aftermarket option is kind of out of my pocket book right now. I will still need headers and an intake for any head swap anyways....perhaps if I find a cheap set of aluminum L98 corvette heads I might consider those.

My GTA does have a MAF system and I will probably be able to tweak the computer systems to work with the new heads.

Someone recomended a good intake for the heads, what do you guys recommend? Please not that my money fund is not large so even though i'd like to I would not be able to get a Ram Jet or similar intake for $1000 or more.


PS Will I need a new cam when changing to Vortec 350 heads?

Thanks!

Ray87Z

I think it was from the Insider hints book, but I'm not positive. I found them posted on another site with no extra details except being from TPIS, they're the exact same numbers F-Bird 88 posted on this forum in one of your links but without citing the source. He had also posted what I believe are their numbers for the AL L98 heads right next to them but since he doesn't specify that's just a guess. I also have their numbers for the stock LT1 and LT4 heads which seem to jive with most published numbers for them. This is copied from the other board, like I said same exact numbers Fbird posted on the thread you linked to by him:

__________________Intake_________________________E xhaust
Lift______.100 .200 .300 .400 .500 .600______.100 .200 .300 .400 .500 .600
CFM_______44 101 155 182 196 202___________41 82 125 137 140 141


That may be true, but if that read high that would put the posted numbers really unusually low for the exhaust, intake within range at least (185/106). If it makes it higher or lower I have no idea but they're already lower than some other sources so.. EDIT - It was the numbers posted by smithtc that you linked to in that large post, if you read the paragraph right under his numbers he mentions about them being converted by multiplying by 1.67 from what the flowbench actually spit out (it was 10" readings to start with, not 11 apparently) Of course I didn't notice it before but he says they had "crappy valve job work" done on them so perhaps that screwed the numbers, who knows, in my book his numbers are tainted somewhat though...

Icepack212

I think the discussion is swaying away from the intended path......

I just wanted to know if I will need a new cam with the 350 votecs and if I need, what kind of intake can I get for not too much cash?

Icepack212

Any responses at all? I could use some opinions plz..


Thx

kdrolt

If you already have a 350 with TPI (per your sig) then you have the L98 cam already, so the answer is no, you don't HAVE to get another cam. You might want one, but it's not required. The L31 heads will work very well with that cam.

You will, however, need an intake manifold that will allow the TPI to mate with the L31 heads --- and IIRC you have only one option for that (SDPP TPI Vortec). I'll add that the L31 heads flow very well, even without porting, but the good airflow from them will be restricted by the TPI runners. That's the main reason why TPI owners resort to intake swaps (see the sticky thread atop this forum).

Do you see the problem now? TPI doesn't flow well at high(er) rpm on a 350, but L31 heads do. The engine can only flow as well as the most restricted part.... so the TPI/L31 combo will make awesome torque but it won't run as well as it probably should at the higher rpms. That's why people mod the TPI and/or replace it. HTH.

Icepack212

Alright, thanks so much for the help. This clears up a lot. I can now plan on working on getting some nice 350 vortec heads and a good intake, and possibly a cam.

Icepack212

Hey all, just wanted to update you on my search for some #906 vortec heads....I found this set on ebay mighty cheap and am now waiting on some data and pictures from the owner. I just wanted to get some opinions whether I should bother looking at these.....the price tag is real low (buy it now price is $225.00 )
I am offering the owner to trade in the #059 heads I got earlier as a trade.

Here is the link to the heads:

http://cgi.ebay.com/ebaymotors/SBC-3...92966981QQrdZ1

Thanks all!

Icepack212

Damn no one is posting.........hey I am going to start saving and researching for an entire engine rebuild someday. But I am having trouble finding some concrete opinions on inakes and which ones I can use with my future application.

* I need a vortec style intake
* needs to be smog/street legal (I live in NY)
* Would be nice to be compatible with a blower or turbo in the future

I'd like to know any opinions from ya fellas, I know the Super Ram is nice, but I hear its not smog legal....please post any other intakes you recommend. (The motor will eventualy be rebuilt with vortec heads, new cam, new base, runners and ....ofcourse the intake...)

kdrolt

You're really asking similar questions to many that have been asked before. You really should read the archived posts, by searching for threads that have Vortec, or L31 head, or 062 or 906 casting numbers (the two L31 head casting suffixes that I can recall) as suggestions. Many people here have asked about them, bought them, tested them, raced them, and still use them. There's more info in the archives that can be answered by your question --- so that's probably why you aren't getting input.

You don't need interactive help. You just need to do some searches, and start reading.