I got my 71 back today. Amazing what the right distributor can do for you when it's tuned along with the carb and the valves are adjusted. Runs great now! Anyway, I was talking with the guy that worked on it. I asked him if the stock cylinder heads were holding me back. He said they might be a little but a new set will definitely step it up. I know aluminum cylinder heads are good for racing. They're good for over 6500 rpm, lighter, easier to port and polish, and so on. I don't need this for my car. It gets driven alot and is never taken to the track although I like to get on it every now and then. My motor is a 350 sbc bored .020 over, flat top pistons, edelbrock performer intake, hooker headers out through 2.5" system, edelbrock 1406 600 cfm carb, CORRECT distributor, Comp Cams .462 int. .482 exh. with 219 and 229 respectively at duration (I think, I can't remember about the duration part), new crank (don't know the specs), and that's bout it I think. I've been looking at World Products. He said that they make a real good cylinder head. He said I could go with Dart or Edelbrock, but I will be paying more just for the name. What do you guys think?

 

performance is made in the heads and they are expensive....take your time and make sure you pick the right one
Summit has lots of choices including there own low buck cast iron take offs of vortec heads and big valve fuelie heads for a really reasonable price

 

World Products Sportsman II heads, real good heads

 

What heads do you have now? My 71 has 186 casting double hump heads. With a little work they support over 400 hp.

I will tell you what is holding your motor back is that wimpy Performer intake. 600 cfm carb is fine but you need a intake that can flow over 5000 rpm.

Look at the rpm rating of aluminum intakes and buy one. Weiand Stealth IMO is a cut above the Edelbrock aluminums.

As for sportsman II. Unless they have changed the chamber in the last few years they are of the old Chevy design. Not a modern heart shaped fast burn. They are also something like 200 cc intake ports and not what you need on mild modded motor. This is just my learned experiences

 

I edited this post, life is too short. I have seen a few posts saying negative things about Sportsman II heads, I have had first hand experience with them and found them to be very good heads and if you factor in the cost they might be one of the best set of heads you could buy for a mild buidup. I made 294 RWHP and 331 RWT with them on my L48 and yes they have Fast-Burn combustion chambers

 

Aluminum heads aren't just for race cars. They will take weight off the front of the car. Shifting weight to the rear of the car helps all areas of performance, breaking, acceleration and cornering.

If this car were mine I would get AFR 180 street heads.

BigBlockk

Later.....

 

Killer street head. 180 is the perfect size for your combo. Leave the old iron heads alone, not worth it.

 

ttt Any more opinions? These things aren't cheap like Bob said and I want to make the right decision.

 

Flow Test Comparison

When it comes to heads right out of the box, AFR takes the cake. Trickflow also makes very nice heads... see for yourself.

I went with the AFR195cc angle plug heads. With the right combo, they're easily good for 500hp.

 

With aluminum heads, its necessary to remember that it reacts differently to heat then cast iron. Cast iron retains heat, while aluminum disperses it. This means don't be afraid to bump up the compression accordingly. Many on the forum are running close to 11:1 compression on pump gas with aluminum heads.

For a pair of interesting heads, I would try to find some of the aluminum corvette heads with 58cc chambers. That should bump up your compression with the flat tops(10.5:1 I think), along with providing much better flow. However a new intake manifold may be required.

Good luck,
trw

 

here ya go, http://www.carshopinc.com/product_in...ts_id/68/HD601 real cheap with new parts. good to .515 lift cam without changing the valve springs. I got them on my Van and it makes 300 hp and revs to 6500 rpm no problem.

 

Those look like rebuilt Iron heads from a 305 or 262.

 

Actually I think you are right Jackson. Either way, if you are not interested in numbers matching they are great heads and I will vouch for them. The van still rocks a solid 15.00 on the strip though.

 

When I ran the numbers for best flow, the AFR was the best I could find. I run 10.5:1 CR on pump gas.

Audie

AFR 195cc SBC Street Cylinder Head
The Ultimate Bolt-on Emissions Legal Street Weapon
The AFR Emissions Legal (versions from 1969-94 with heat riser, CARB EO #D-250-2), 195cc intake port small block Chevy cylinder heads are available in your choice of straight or L98 angle plug versions. These heads feature a 74cc or 68cc combustion chamber with a 64cc exhaust port and a 3/4” thick head deck (ideal for nitrous or blower applications). The 68cc chambers are designed for flat top or dished pistons; domed pistons will require additional machining. Standard valves are 2.020 intake and 1.600 exhaust with AFR’s hardened ductile iron interlocking valve seats. The exceptional flow characteristics, ideal operating range of 2000 rpm to 6500 rpm, 23º valve angle, and standard valve spacing make this the perfect street head for 350 cid to 400 cid engines from 1955-86. Available for 1987 to present engines with center bolt valve covers and 2 center intake bolts at 72º angle. No special parts are required.

Note:
Hydraulic roller cams typically experience valve float at 5800-6000 rpm because of their fast ramp rates. AFR suggest you upgrade your springs to AFR part #8032, 1.530 O.D. with higher spring pressures and use our Patented “Hydra Rev Kit” to reduce chances of valve float associated with rpm 6000 or higher.

 

When I was talking with him, he said that a 58cc or 64cc head would be best for my motor and the way it's set up. I guess I will be looking for this size head as he knows the ins and outs of my particular motor. Thanks guys, keep the ideas and replies coming.

 

World sportsmanII heads are by far the best "BANG" for the buck. They come bare or completely assembled, with up to .600 lift out of the box. they lend themselves easily to porting for more bang and can be upgraded without more machining.

vic

 

Been looking at heads too ... for a 406 in-process. AFR 195 w/74cc looks right for my flattop combo. However, just got this back from afr today "We no longer sell a "Non-emission" small Chevy street head...."

Meaning afr no longer offers a street head that does NOT have a heat riser port. They did ... old p/n for 195/74 straight plug w/ NO riser was 1035 ... 1035 no longer available.

 

Yup just checked it out and they are in California, they must have come up with a law prohibiting non heatriser heads on the street