worked stock or gt40p heads

[lazyike]

I was wondering if a guy spent 500.00 on the stock heads what could he end up with??? Or would I be better off spending 500.00 or so on some gt40p heads?

thinking about gt40 intake.
heads???
f-cam

 

[fivelitercoupe]

I'm also curious about this.....

 

[shawn13]

PM thumper460 I think you will like his work better than gt40p heads

 

[rdksek844]

Check out this place. Their exhaust flow is higher than thumpers but the intake flows are about the same. Thumper is somewhat cheaper too.

http://www.powerheads.com/SB50.html

 

[rdksek844]

Here is another really good site to compare heads. It will even graph the difference.

http://www.allfordmustangs.com/Detailed/630.shtml

 

[fivelitercoupe]

Thanks for the help, those are some good sites. Yea I think I would rather go with the thumper heads over the GT-40s but thats just me. Thanks again...

 

[noslow5_0]

how much does thumper charge for a set of ported heads???? anyone got any kinda numbers his heads put down???

 

[BlackFox5.0]

Unported GT40P's will outflow the most home ported E7's. Unless they were REALLY worked, and have bigger valves, they will not outflow the stock unported GT40P's

The P's also have a smaller combustion chamber and will raise your CR to 9.5:1 (FYI, GT40's will lower it to 8.8:1)

 

[rdksek844]

I think you will find that both powerheads and thumpers heads outflow gt40 p heads. you can compare flow results on the above website. You can find thumpers flow numbers on his site.

 

[rdksek844]

@.500 in lift
power head flow 217.2 intake
gt40p flow 196 intake

power head flow 175.5 exhaust
gt40p f flow 139 exhaust

power heads do have larger valves
1.9 v.s 1.84 intake
1.6 v.s 1.46 exhaust

heres thumpers website to see his results
Oh and he uses stock valve sizes to achieve higher than gt40p heads
218/154 v.s 196/139

http://thumperoforangepark.com/

 

[MustangMulch]

I'm pretty sure Thumper's heads will outflow the P's. And keep in mind that if you use Thumper heads you can use any headers you want. You won't need special headers like u will with the gt40p's.

 

[rdksek844]

I'm pretty sure Thumper's heads will outflow the P's. And keep in mind that if you use Thumper heads you can use any headers you want. You won't need special headers like u will with the gt40p's.

Another good point. You might get the gt40p's for less than thumpers or power heads, but you will have to buy other headers.

 

[tom2001gt]

I just bought a set of powerheads on there site they have the flow charts.

 

[90mustangGT]

It's kind of like this, GT40's will outflow E7's, ported E7's will out flow GT40's, ported GT40's will outflow ported E7's. This counts that the heads are ported right by someone who knows what they are doing. Thumper has been doing it since before the heads came out, and had done several hundreds of sets. Some people think all porting is drilling out the ports so they are larger. There is much more to it than that, it's about increasing flow by altering the shape and size of the port. Beyond that I don't know.

I have been running Thumper's for more than a year now. Made a world of difference. I think they are well worth the total of $700 I paid including the double valve springs. My weak points are the suspension that I am currently building and probally the B cam, but not the heads yet. They will come off the car when the engine comes out. There is nothing like showing someone that you still have E7's on your car after busting thier balls. The only giveaway is the blue paint which says they have been off the car.