I'm sure many of you know i have a base 350 with the performer rpm package, and im going to be swapping the cam for a xe262 to pick up some big numbers especially down low. The engine would make even better numbers with higher compression so thats where these heads came in.

Specs:
</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">
58cc, Straight Plug-Assembled (Each)
Perfect for use on 262-307 cubic inch small blocks. 1.940 x 1.500 valves, 170cc intake runner, 1.250'' single spring, 100# @ seat, .560'' max lift.

Material: High density cast iron
Valve Seats: Integral intake,hardened steel exhaust
Valve Size: 2.020'' x 1.600'' (1.940'' x 1.500'' for S/R Torquer 305)
Rocker Arm Studs: 3/8'' shank, screw-in style with hex shoulder furnished
Accessory Flange: Stock locations, 7-bolt universal pattern

Included In Assembly: Manley Street Flo stainless steel valves (1-piece forged, with undercut stems and swirl-polished heads), ring and band valve seals, valve springs, Manley 7° chrome moly retainers, keepers. </pre>[/QUOTE]The big thing here is hte 58cc combustion chamber, which according to desktop dyno will get me a compression ratio in the 10's. Is that too high to run on 91/92/93 octane? According to Desktop Dyno the smaller valves seem to sacrifice 3-5 ft/lbs from 3000-4000rpms, which isn't much, but these heads put my torque curve over 400 up to 4500rpm.

At $380.00 each (assembled) they aren't too expensive, but my question is are they worth it? Will they really make the difference im seeing simulated?

Are there any other heads smaller than 64cc that would net me a better compression ratio?

So you need something from 58cc-62cc for 10:1, 64 for 9.8ish.

The only other "budget" heads in that catagory are:

1. "good" GM 305 heads that came on TPI cars. 58cc

2.Vortecs 62cc

3.GM's TPI-era Corvette aluminuim heads 58cc

4.GM's 350 TPI heads (64cc heads, I think.)

And of course double-hump heads if you can find them cheap.

Keep in mind that DD2K isn't accurate either.

64cc would be lucky to get me 9.3:1 according to what everyone here has told me in the past, thats why the 58's caught my eye.

Is 10:1 able to run on 91/92/93?

Should run on 93, but there are a lot more variables than just the 10:1 CR. But typically 10:1 with iron heads is considered do-able on 93 octane.

**I edited my post above to display the cc's of each head**

Can you post your current setup again? Gearing, convertor, intake, exhaust, etc?
The 58cc heads will put you right about 10:1 with stock type dished pistons. I wouldn't use the xe262 with that much compression myself, as you will have about 200psi cranking compression along with a poor piston design AND a conventional (non fastburn) style combustion chamber, which IMO is going to ping like crazy on anything less than 93 octane AND a razor sharp tune. A 64cc chamber would be better, putting the compression in the low 9's, which is about perfect for the xe262 cam. Consider the 67cc S/R torquers with the 2.02/1.60 valves. This will put your compression right around 9.0-1 or so, allowing easy pump gas driveability and with the xe262, will make TONS more power under 5500 rpms than your current setup.

the raising of hte compression has no significant impact from 8.5 to 9.0, for $800 bucks im only going to gain 20ft/lbs max on the chart.

Right now i have the base gm crate motor with:
- Performer RPM Cam (bleh!)
- Performer RPM Intake
- Perormer Carb (600cfm) (plan to upgrade to 750 with the new cam)
- Hooker 1 5/8 headers
- Flowmaster dual 40's with H pipe (2.5 i think)
- and the little things like hte recomended valve springs and timing chain for the cam.

I have 300 bucks give alloted to me for christmas, so the first thing on my list was either hte xe262 or the xe268 if i change hte heads. In addition im going to get hte jegs special HEI distributer (still running on points :| ) for 100 dollars putting me close to $300. I'm pretty positive i can squeeze one sub $200 item in there (even if i have to pay the difference) but i dont think there is anything else i can possibly due to this motor without ripping it apart (which isn't a possibility). And no, im not putting NOS on it ;)

The problem is that i dont want to spend $800.00 for 20 ft/lbs, its just crazy, for a daily driver that wont get me much.

There's no junkyards in your area? You could get a decent HEI for 20bucks or so, get a recurve kit for 10 bucks and and a crane adjustable vacuum advance kit for another 20 bucks.

That's half the price of the Accel and will perform just as well with the new springs from the re-curve kit.

Whatever direction you go with the HEI, remember you'll also have to buy new plug wires, they don't interchange. A decent set for you set-up would be the Borg-Warner Select wires.

Sorry...you posted about heads, so I assumed you was changing heads. My bad.

Do you have any idea what rear gearing you have in the car? Is the torque convertor stock, as far as you know?

FWIW, Chevy high performance magazine done a buildup series on the goodwrench style engine you have. As your engine sits right now, with a little pocket porting on the stock goodwrench heads (nothing fancy) and the heads milled a bit, and using a felpro 1094 head gasket to help get the compression up to an actual 8.4-1, and a xe268 cam, it made a "magazine" 335hp. I know of a late 70's nova with that exact setup, a 2800 rpm stall convertor, and 3.73's that runs low 13's. Something to think about anyway.

Yeah i was asking about the heads initially but i guess it turns out that 58cc is too small of a combustion chamber unless the car is perfectly in tune which it wouldn't be.

Supposidly my car has a rear out of a buick, or so the previous owner says. But from the outside it appears to be your standard 10-bolt open which makes it a 2.76 right? My dad thinks its a 3.73 but i dont think it is. I asked on the tranny forum and they said it would be expensive to upgrade the gears because id need a new carrier and everything and id be better off just getting a whole axle with posi, which is about 1200.00 more than i want to spend right now ;)

The tranny is a TH350, it was rebuilt in the early 90's (or replaced i cant remember what she said), so it most likely has a generic stall convertor, so id assume 2500? I dont have a working tach, we think its fried, we tried replacing hte printed circuit but none of the gauges respond still, all i have is a speedo :(

As for the HEI, you cant go wrong for $100.00 and I know it will work flawlessly. There is one sweet junkyard around here filled with every pre 80's car you can think of, but its restricted access, nobody can get in, i can only imagine what parts i could get from there if it were open :( Other than that there are no real junkyards around here.

Ok...heres what I would suggest doing first. Before you change anything, go pick yourself up a cheap tachometer. Most parts stores carry something like sun or sun-pro or whatever they are called...you can usually pick one up for about $30. Then, follow someone down the highway at 60mph and see what your rpms are. I usually suggest following someone with a later model car that you know has never had the tranny changed and still has OEM sized tires, that way you can be pretty sure their speedo is close. I also assume with the big performer rpm cam, it probably wont spin the tires. If it won't, you can use a tach to get a better idea of your convertors flash stall speed. Just stomp it from a dead stop, and note the rpm that the tach initially jumps to before the car moves more than a few feet. If it is a stock convertor, you will probably only see the tach flash to about 1400-1500 rpms.
Without a tach, you can also determine your gear ratio pretty close by jacking both rear wheels off the ground, and marking the driveshaft and a rear tire. With the tranny in neutral, rotate the driveshaft and see how many times (and fractions of times) the driveshaft rotates for 1 complete revolution of the rear tire(s). You can determine if you have a posi rearend by rotating one tire, and if the other tire rotates in the same direction, it is a posi. If it rotates the opposite direction, it is a pegleg. If it is an open (non-posi) rear end, when you rotate the driveshaft the one tire that spins will spin at twice the rate of a posi rear. For example...

posi rear, driveshaft turns 3 and 3/4 turns for 1 turn of the tires is a 3.73

open rear, driveshaft turns 1 1/2 turns for 1 turn of the right rear tire (normally) is a 3.08 gear.

If you think it is a 2.73 rear end (very common gear BTW), with a posi you would rotate the driveshaft 2 3/4 turns for 1 rotation of the rear tires, while with an open differential it would be a little under 1 1/2 driveshaft rotations for 1 tire rotation.

Hope this made sense. The more that we know about what you have to work with, the better parts recommendations we can make.

Ok, yes you are dead on with the "cant spin tires" which is annoying (seriously thats kinda embarrassing lol).

I dont need a tach, you basically recreated exactly how the car performs, it doesn't go high with the rpms, deffinantly right around 1400-1500 because i know the shop tuned the carb and set hte idle to around 800-900, and the car really pulls from 2500 ish, so you hit the nail on the head.

The 262 is deffinantly going in the car, unless the sacrifice at the bototm end of the 268 is worth the gain in the top end (anyone have an opinion?)

Its deffinantly an open rear but i read i have to have the left tire on the ground before i spin the right tire, which i didn't do. Ill get back to you with the gear ratio.

You really should get a cheap tach. Its a nice little tuning aid and will really help out if you ever race at the track.

I thought I was shifting at around 4500RPM without my tach, then I installed my tach and realized I was only shifting around 3800RPM and leaving about .2 seconds (1/8th mile, even more in the 1/4) on the table.

Tachs are fun to have.

yah, but i dont go to the track, i dont have time, this thing is my daily driver, id rather get the factory tach working first.

My dad mentioned the idea of replacing the harmonic balancer and other pulleys since hte whole front of hte engine is coming off anyway, are there any gains to be had doing this?