Tripower delight

Thinking about buying a pair of alumlnum heads
I have a 427 two bolt main engine with a mild cam
Looking to get a little extra horsepower what brand heads should I go with.

ajrothm

It really depends on the budget you want to spend, and if you're going to change the cam/intake with the heads.. Also need to know what pistons are in your motor?

Most of the aftermarket aluminum heads have fairly large combustion chambers (like 119cc)....those will likely lower the compression on a stock 427, thus you would LOSE power.....

I would probably try the TrickFlow 280 ovals or Brodix RaceRite 270 ovals. (if you have enough dome on the pistons)

Edelbrock also makes a 454-O, high compression head with 100cc chambers which might work ok for you.... All depends on what pistons you have. You're really gonna need to upgrade the intake manifold to something like an RPM or RPM air gap to really see any difference at all with the heads....same goes for the cam really..


***ALSO beware of the raised exhaust ports on lots of the BBC heads, your headers/side pipes may have issues... The Brodix RaceRites have the stock exhaust port location I believe.

bluedawg

How much does the port have to be raised to cause issues?

Rebelrob

Very little.... = fitament issues .25" give or take.

bluedawg

Thanks. I wonder if afr has these issues.

Tripower delight

AFR heads changed the degree of the ports to increase air flow they even say you have to modifly your headers

Tripower delight

I will most likly pull these heads and have them rebuilt,also swap out the cam for a hydrualic roller cam whitch I wanted to do. Thanks for the input.

Super6

Besides a performance improvement, it's 70 lbs. off the car. Don't throw in the towel just yet. What heads do you have now? I went from 10.5:1 CR in 109cc stock rectangular port 840 heads to GMPP/Edelbrock 110cc combustion chamber large oval port 290cc runner heads. A friend went from a stock 427/390 head with 10.25:1 CR and a 435 cam to the same heads. Stock exhaust locations. I have a set of the smaller 100cc chamber heads on my engine now with some work done for 11:1CR. Brodix Race-Right oval ports are good heads (probably flow better than the Edelbrocks), but they don't come with the exhaust stud holes heli-coiled. Brodix offers it as an option though.

rponfick

I agree with some of the above comments. I used Brodix to eliminate the raised exhaust port issue. I wanted to use stock BB manifolds and didn't want the fitment problems.

Ralph

Rebelrob

Yes AFR's are raised, that's what I have. I think its even more of a challenge to get side pipes to fit vs standard long tube headers.

zwede

The Edelbrock heads have standard port locations, and are available in small chamber (110cc and 100cc) if you have low compression pistons. They're a good choice for a street car. Don't make as much power as AFR or Brodix, but unless you race it you'll never notice.

TimAT

http://forums.corvetteforum.com/c3-t...lum-heads.html see post #10
Your results may vary. Just my experience and what I did to confirm how much raised port I could use without problems.

bence13_33

I'm running 320cc intake runner heads from Pro Topline. They are aluminum with 119cc combustion chambers and 2.25/1.88 valves. I'm pretty sure the company has long been defunct. I got them probably 6-8 years ago for $1500 complete and shipped to me. I saved around 80lbs in weight. I will admit that even with the torque of my 454 and 4.11 gears with a 4 speed....the loss in bottom end was substantial. I have probably 50-100 more horsepower since changing my setup, but anything under 2500-2800RPMs feels very sluggish. Once you get past that RPM range you can't hit the next gear quickly enough (it does rev way faster). Stop light to stop light however is not as much fun as it used to be.

bluedawg

It would be worth while to contact Mark Jones at vortecperformance and see What it would cost to have your heads ported, The man is a God to porting big block chevy heads.

Rkreigh

I've got a set of procomp CNC bare heads

these are a "china clone" ebay head but the quality has gotten much better and the flow a ton (around 400 cfm)

I'm going LS so they are going up for sale (need $1600 for the pair, again they are BARE)

nice looking head

I like the musi edlebrock stuff too but you're gonna pay and for a bit more pop on a street car, I doubt you'll see it

budget on a nice solid or high end hydraulic roller the cams make gobs of midrange and will pull hard up top

use some LIGHT valves and good springs to match the cams. BB chevy have some heavy stuff and RPMS become an issue with high lift hydraulics and the modern oils don't hold up as well with flat tappet stuff unless you get the right oil!!!!

I've also got a 496 BB chevy "on the stand"

2 bolt main 4.25 stroker, with a nice high rise intake, mild street cam that pulls to 6 k and the combo makes a nice round 560 hp with that much torq to boot

probably all you'll need for a while

PM me if you'd like details.

Les

Good info here, as always. The Edelbrocks are nice if you need small chamber heads- pretty much the only choice in aluminum and that's why I have them. If you can run bigger chambers, the Brodix heads are very nice- that would be my choice, since they don't have raised ports and they flow really well. Combine either with a well matched cam and a set of headers, then you'll be having some fun!

bluedawg

So are you running long tubes or side pipes? If long tubes what kind of issues did you encounter?

bence13_33

The 119cc chambers are pretty big and would drop your compression considerably . The lower compression by itself won't cost you much in terms of horsepower...what will cost you with the lower compression is the ability to run a larger cam to compliment the heads. I run side pipes and supposedly my heads have 3/8" or 7/16" (it's been a while I can't remember) raised exhaust ports and the Hooker side pipes bolted right up much to my surprise and to this day I have no idea how??? I bought the side pipes off of eBay a long time ago for like $550 shipped to my house. I would definitely consider a larger O-port if it sees a logic street use. Like I said in my first post the 320cc intake runners definitely hurt my port velocity and bottom end. I don't mind much because I am more worried about my HP and 1/4 times and fan deal with a little bit of sluggishness from stop light to stop light.

Syl1953

I was recently told by a head rebuilder/new head salesman that Brodix is the ONLY head cast in America, all others are cast in China and machined here. If it makes a difference to you.

bluedawg

was the sales man selling brodix?