GT 40 vs performer

[WRXracer]

What is the real performance diffence between the heads..

 

[302 coupe]

performer heads are much better. I consider GT40's not so much of a performance head, but rather just not as bad as the stock castings. They are good for a mild engine but they do leave a lot to be desired. If they're the same price, I would definately go with the edelbrock performers. Do a google search on Stan Weiss cylinder head flow data, very comprehensive list of flow vs. valve lift for just about every head made.

 

[66P51GT]

Flow data from Edelbrock
Look at the second row for Performer heads.

<TABLE width=690 border=1><TBODY><TR><TH>Part Number</TH><TH>.100"
Intake/Exhaust</TH><TH>.200"
Intake/Exhaust</TH><TH>.300"
Intake/Exhaust</TH><TH>.400"
Intake/Exhaust</TH><TH>.500"
Intake/Exhaust</TH><TH>.600"
Intake/Exhaust</TH><TH>.700"
Intake/Exhaust</TH></TR><TR><TD align=middle>#60229, #60289, #60329, #60379</TD><TD align=middle>72/57</TD><TD align=middle>132/104</TD><TD align=middle>183/142</TD><TD align=middle>216/159</TD><TD align=middle>245/170</TD><TD align=middle>249/174</TD><TD align=middle>244/175</TD></TR><TR><TD align=middle>#60259, #60359, #60399</TD><TD align=middle>70/57</TD><TD align=middle>128/104</TD><TD align=middle>183/142</TD><TD align=middle>219/163</TD><TD align=middle>251/170</TD><TD align=middle>255/174</TD><TD align=middle>246/175</TD></TR></TBODY></TABLE>

 

[66P51GT]

Better Yet...
This is what I was looking for: http://home.isoa.net/~mharrisj/fordhead.html

Enjoy!

 

[Mosse]

Somebody in this forum wrote that y303 is basicly same as edelbrocks older performer? I really don´t know this as a fact. It is really hard to tell the difference, if both are aluminum and don´t have to think of weight difference... At least here y303 GT40 heads are much cheaper than edelbrocks (new). If I´d be thinking changing my -69 heads, Id go to AFR , I think, but maybe I´m just brainwashed thatway... ???

 

[WRXracer]

oh

oh GT-40X FRP seem pretty good for the price..

 

[1969mach1351]

Don't mean to hijack but is there a way to tell the difference between GT-40 X and Y with them on the car?

 

[66P51GT]

I took the online data and averaged flow for the Edelbrock Performer and GT-40X heads and created the chart below. I compared the flow numbers to a stock 289 head.

GT-40X Heads flow 24% better than stock.
Perfomer 5.0 Heads flow 30% better than stock.

This is how they stack up against the competition. These values are average Intake and Exhaust accross a lift (.200 - .500). They are sorted in order of highest average flow. I didn't have complete data for these from (.100 - .600) so this could affect the orders, but not by much.

 

[302 coupe]

there's a guy on ebay with a new set of y303's for $699 buy-it-now. no, its not me, just thought I'd share.