gt-40 aluminum heads

[homeroV8]

I want the easiest heads to install, direct bolt-on and assembled.For now I don´t care much about porting, etc. Do I need special plugs and gaskets? Which ones? I want the compression as stock as possible. 64cc?
I tried to find the answers in the previous posts, but didn´t succed.
Thanks a lot, I would really appreciate any comments.

[fiveohpatrol]

If you don't care about porting, then do NOT get the GT40 aluminum heads. I recently saw a flow comparison of the GT40X vs a set of ported E7 heads. The GT40's had higher PEAK flow, but average flow across the lift range was actually about the same on the 2 sets of heads. Thats not information I would want to hear if I spent that much money on those GT40's.

Why do you want to stay close to stock compression?

What sort of budget are you on?

I would check out JD's performance for a set of TFS aluminum heads. They have them for just over $900, and will KILL the GT40's.

[jim_howard_pdx]

If you take the time to read my posts on speed secrets 1-5 you will see that in order to make big power, you only need to build a balanced engine.

For a street rod, I prefer the Trick Flow Twisted Wedge Head. Port match this to the intake and exhaust of your choice. With a cam of at least 486 lift and 215 duration at .050 lift, you can expect one horsepower per cubic inch. Go with an E or X cam, and you can be solidly in the 370 hp range.

I like trick flow for three reasons. Number one, they have the best water jackets for any Ford engine I have ever seen. This means adequate cooling that will prevent head warp. This is critical on aluminum heads.

Second, they will easily make 1.2 to 1.5 horsepower per cubic inch with minor mods.

Third, the intake valve is rotated, so it produces unbeatable swirl as the valve decends right down the middle of the cylinder. This gives the engine more opportunity to fill the cylinder up with fuel and air before the mixture collides with the cylinder wall and gets disrupted.

The most important reason, is that they are so close to the YEATs Nascar heads in compression chamber technology that it defies description. The compressed fuel and air are squished to a 61 CC combustion chamber that puts the spark plug right in the dead center of the cylinder. Burn is EXCELLENT.

So avoid the straight line heads like the plague. There is a reason the Cleveland heads and the Big Block Chevy and Ford heads flow so damn well. They use cantalever valves that get the fuel dumping down the center of the cylinder.

Hope this helps. My slightly ported Trick Flows Flow 249 CFM on the intake and 198 CFM on the wet flow bench. This kind of flow is simply outstanding on a .496 lift intake and a .520 lift exhaust. No need to flycut the pistons either.... Going to a .560 lift cam puts me at 290 CFM. This is awesome.

So buy a head you can grow with, and one that I have run now for six years. I have cleaned up on many a Z28 and Corvette that said, oh an early mustang, and when I wholloped them, they really looked MAD.



Simply unbeatable.

[homeroV8]

Wow! Talk about teaching! Thanks really, it made me understand a lot better the principles of flow. I meant near stock compression because of low quality gas, sometimes, in my area.. Well. I´d like to spend $1000, including headers and intake, what practically excludes aluminum heads, unfortunately. I´ll probably opt for gt-40p, so I can make a reasonable upgrade (plus header, tb and intake).

[jim_howard_pdx]

See what you can get on EBay. Go with an Edelbrock RPM intake manifold if using a carb.

If aluminum is beyond your reach, see if you can locate some World Product Victor Jr heads. These are inline, OUCH, but use 1.97 and 1.60 chevy valves and have a 170 CC intake port that flows pretty nice. I believe the combusion chamber is either 60 or 62 CC.

These are Iron, I used to buy these from PAW for 649.00 Get the RPM manifold and buy some Felpro 1250S gaskets. The S is important. Make sure to get the 1250 "S"......

Then buy a carbide oval cutter, mount it on your electric drill and port match the heads to the gasket. Then mount the heads on the car. If you have hydraulic rollers, make sure they are in first.

Then just lay the intake on top of the head. Mark the centerline of the head's port and the intake's port with a grease pencil and see how well these lines match up unbolted, then put in a couple bolts, does it shift the lines? Just drill out the intake bolt holes to a larger hole size allowing you to keep the centerlines together. Now put the 1250 S gasket on the head surface with HiTack to hold it in place. Make sure it is perfectly centered around the ports you matched to the gasket. Then lay the intake down and mark where your intake will intersect the head surface.
Then pull it off and see how the intake manifold matches vertically. Now you can pull off the 1250 S and using the vertical point match and the centerline port match you can now scribe where the intake needs to be ported to match the heads.

Your carbide cutter will make fast work on the aluminum. Use a rat tail file to smooth the gubbers and you are now port matched. I do the same on the exhaust ports. Make sure you run at least shortie headers of at least 1 5/8 primary tubes. I would look into the Flow Tech headers, and use full length if your car is not lowered. I use shorties because my car is 2 inches lower than stock.......

You can expect 1.0 to 1.1 hp per cubic inch with at least a .480 lift cam. Stock cams are around .445 to 455 lift.

Hope this helps.

[88workcar]

IF price is the reason, go with POWER HEADS they flow a better average the EDELBROC alum heads. They are completely bolt on and a direct bolt on. For the money you will have to buy used heads to equal thier performance. You said ported and flow is not your concern, but why not get the best that YOU can afford. These heads, a cobra or professional products intake, and some $90.00 1 5/8 long tube headman headers, and the stock or an E cam, and you will be surprised and flying. GOOD LUCK either way you go.

[HotRoddin]

Originally posted by jim_howard_pdx
If you take the time to read my posts on speed secrets 1-5 you will see that in order to make big power, you only need to build a balanced engine.

You are one of a kind Jimbo !