with my engine combo, I have about 9:1 with a steel shim headgasket, and 8.6 with a stock gasket.

I want to run the stock thicker gasket(got tired of replacng the shim ones) So i need my heads milled to get more compression.

How much should I have it milled to gain one more point to make it 9.6:1?

The heads are stock L-82 76cc chambers

 

What casting?

If they're 882, 993, or 624, throw them in the garbage and start over. They're not worth putting money into. You can put lipstick on a pig all day long, it'll still be a pig. the "this is what I've got" argument doesn't wash, either. Convincing yourself that the only thing you have that you can put the lipstick onto is a pig, still won't make the pig any prettier.

In fact, you can probably mill them into a set of 416s, put 1.94" intakes in them, and get 8-10% more power than ANY of those crappy 70s smogger castings will make.

 

You'll have to mill off about .006/cc (depending on the actual head), and you need to drop ~ 12cc, so thats like... 0.048 off the head. +/- So, in short thats way too much. Forget that idea. The best idea is the one above, or run what you've got. I wouldnt take more than .020 off a factory head, unless you like being risky. You can... but not advisable.

 

Yeah, I guess your right about them, I got them for free so I didnt complain lol.

I think im gonna save up my money after all the rear end stuff is figured out and get a pair of World SR torquer heads

Any opions on the Sr torquer heads?

 

Not the best; but ALOT better than old smoggers.

What casting are they?

 

For what its worth

I just had a set of 416's milled dowm .015" and only managed to shed off around 2cc. But I used a syringe to cc the chambers, so i may be off a cc or two.

 

SR torquers are called SR because that means "stock replacement". Ie, if your heads are cracked and you need a replacement to stop oil getting into coolant (and vice versa), sure thing, they'll keep the mixture inside the engine - but don't expect miracles.
They're not really designed to be a high perf racers head. Maybe save a bit more and get something more of a high perf head, an entry level 180cc type might be good for you.
Or as mentioned, look into porting some 416's, i'm another happy customer with that route.

 

Do the 416 heads flow better then the world SR torquers?

they come on 350 only or were 305 with them to? theres probably no difference right?

i could probably pick up that casting cheap from a PNP yard near me

 

416's came on 305's in the 80's only.
They would flow a tad less than SR torquers, but are essentially free, that's the beauty to them. Bust out a die grinder and work some magic and you've got some rockin' heads, for the price of a few tanks of gas.

 

I looked them up and they were made from 80-86. That doesnt mean they have the thin domes do they?

those 58CC chambers will make my compression 10:1 with my pistons, thats not too much for premium gas?

BTW this is for a 350 not a 305.

 

You have to remove 5.6cc's from a 76cc head to make up the difference between a shim type gasket and a felpro composite gaskets volume.
This usually involves removeing .060" from the heads deck. If your heads have 1.94" valves you should be able to do it. The physical limit for flat milling is the intake valve seat. This will get you to 70cc's.
Why not just cut .005" to .010" off the head decks to true them up and reinstall with the shim gaskets? Install them clean and dry (oil free). No sealers, paint, copper spray, etc et... retorque the head bolts after a few warmup cycles. If you have a properly functioning cooling system you should not have a problem with leaking shim. gaskets. I've never head a shim gasket fail. Even on 12.5:1 high compression motors. Leaking head gaskets (thin shim or other wise) indicate a cooling system that is not right or improper engine tuning (detonation, lean AFR, over advanced timing, too hot)
Do you have problems with exhaust headers gaskets too?

If you were to rework a set of 416 heads with larger valves and porting for a 350, the chamber size will be bigger then 58cc. Typically around 61-62cc after relieving the chamber walls for the larger 350 valve set. Use 1.94x 1.60" valves.

 

Cooling problems can cause headgasket failure? I didnt know that could happen, I had a aluminun edelbrock pump and my car always ran at 200-210 and got there fast and worked my fans over time, so I replaced it with a stock water pump and 198 is the highest its been since, and takes a lot longer to get that hot. guess thats why the shim one leaked after a month

thats good news about the chambers opening up to 62cc that will give me about 9.7:1 which is better then 10:1 that was iffy, I know 9.7 will work with premium.

Im gonna keep my 76cc heads as there are on the engine right now, cause I got a nice looking pair of 416 heads today from a PNP yard, took them off a 84 caprice. picked them up for 90$

time to visit my buddies at the machine shop. there gonna know me by name pretty soon

Will i get a horsepower increase from more compression and better flowing heads?

 

Oh yeah big time that will cause headgasket problems, local machine shop guys swear buy using shims. Id say you should address some other problems.

 

Well, I have one last question, were the heads on roller blocks or were they all still flat tappets?

my heads came from a 84 caprice, somone yanked the cam, lifters, and pushrods aleready...

my book says they were made from 80-86 which should be tappet. im asking just to be sure to get the right pushrods.