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  • Fox 5.0 Mustang Tech

GT-40P heads, stock cam & 1.7 rockers?

  • Thread starter Thread starter 94GT40
  • Start date Start date Apr 2, 2005

94GT40

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Mar 30, 2005
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Apr 2, 2005
#1
  • Apr 2, 2005
  • #1
I also posted this over in the 94-95 tech section. I hope it's OK to post it here too...

I'm going with the Cobra intake, GT-40P heads, sticking with the stock cam and will be using the 1.7 aluminum roller rockers. A few questions:

1. Does anyone here have a similar combo? If so what rwhp and rwtq numbers are you putting down?

2. From what I've read I will need to use some valve covers with more clearance. Any suggestions for inexpensive valve covers?

3. Will I need to do anything special to the Cobra intake to clear these valve covers?

4. I shouldn't have any piston to valve clearance problems using the stock cam, should I?

5. I read that the 94-95 Cobra's that used the 1.7 rockers actually had a milder cam than the 94-95 GT's. Is that true? It kinda makes sense in that they were only rated at 240hp.

6. How does the "Thumper" ported heads compare with the GT-40P heads? I almost ordered the GT-40P's from Tri-State, but I'm still considering other options.

A. Tri-State modified GT-40P's 1.94/1.54 for $470 shipped
B. Thumper E7 ported heads for $595 + shipping
C. Buyfordracing GT-40Y's for $749 + shipping

What's the best bang for the buck for a low budget daily driver?

Thanks in advance for any help.
 

25thmustang

Mustang Master
Sep 5, 2003
2,021
85
99
Montgomery, NY
Apr 2, 2005
#2
  • Apr 2, 2005
  • #2
I posted my reply there, about my dads 91. But he also uses stock valve covers!
 
B

BaXTeR3221

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Jan 12, 2004
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Orange County, NY
Apr 2, 2005
#3
  • Apr 2, 2005
  • #3
I run 1.7's on my car with the stock valve covers. Unless the heads require a different set, which i doubt, you should be fine w. the stock ones.
 

94GT40

New Member
Mar 30, 2005
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Apr 2, 2005
#4
  • Apr 2, 2005
  • #4
BaXTeR3221 said:
I run 1.7's on my car with the stock valve covers. Unless the heads require a different set, which i doubt, you should be fine w. the stock ones.
Click to expand...

Thanks... Did you have to modify anything on the inside. What do you think of the Proform rockers? I hear that they are good quality for the price.
 

notchback

Founding Member
May 30, 2000
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St Clair Shores MI
Apr 2, 2005
#5
  • Apr 2, 2005
  • #5
w/ those head choices , i would buy the p's

port the crap out of them....exhaust mainly...some intake work, and remove the bump

should be good for 300 hp w/ the port work...275 w/ out
 
B

BaXTeR3221

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Orange County, NY
Apr 2, 2005
#6
  • Apr 2, 2005
  • #6
94GT40 said:
Thanks... Did you have to modify anything on the inside. What do you think of the Proform rockers? I hear that they are good quality for the price.
Click to expand...

I didn't actually put the rockers on the car, they were there when i bought them. I had thought they were stock cobra roller rockers, but they are actually crane cams. I dont know how much difference they make on my car since its mostly stock, but i would think with an intake and heads, the extra lift would be helpful since your staying with the stock cam.
 

Paul Perreca

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Mar 30, 2005
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Apr 2, 2005
#7
  • Apr 2, 2005
  • #7
the 4.6L tech has a section titled, "Modification Survey Thread " and this is what we should have in the 5.0 tech section as well, i would be very interested in seeing everyones combos and thoughts about parts !!!!!! I dont want to be the one to start it though, because I don't know how to get it to be a sticky, but we should have a sticky over here!!!!!!
 
S

shewitt

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Aug 18, 2003
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Newnan GA
Apr 2, 2005
#8
  • Apr 2, 2005
  • #8
I have heard from people that its not a good idea to go with 1.7 with gt40p heads. But at the same time people told me not to use a supercharger with my gt40p heads.
 

94GT40

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Mar 30, 2005
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Apr 2, 2005
#9
  • Apr 2, 2005
  • #9
shewitt said:
I have heard from people that its not a good idea to go with 1.7 with gt40p heads. But at the same time people told me not to use a supercharger with my gt40p heads.
Click to expand...

A tech article in "5.0 Mustang" magazine said that the 1.7 rockers with the stock cam was "ideal" with the GT-40P heads.
 

twolo4u2c2

5 Year Member
Apr 10, 2003
330
6
29
reading, PA
Apr 2, 2005
#10
  • Apr 2, 2005
  • #10
OK.....I have almost the same config before I went with a 347. Only difference is an e-cam & I have the gt40 intake(pretty close to the cobra). I made 267hp and 315 tq at the rear wheels and my 302 had 170k on the ticker. thought that was pretty good. oh My gt40p has 190/164 valves to so I guess it not real close but I hope it helped.
 

OL' WHITEY

New Member
Jan 28, 2004
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Weddington, NC
Apr 4, 2005
#11
  • Apr 4, 2005
  • #11
My car made 236hp / 386 tq. with stock cam, stock E7 heads, 1.7's and a cobra intake. Also 70mm tb, 73mm mass air and shorty headers (see sig.). 128K on the ticker! P heads should get you another 20-30 hp at least.
 
S

shewitt

New Member
Aug 18, 2003
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Newnan GA
Apr 4, 2005
#12
  • Apr 4, 2005
  • #12
Im just going by what people have wrote on this board about 1.7 and gt40p's.
 

94GT40

New Member
Mar 30, 2005
110
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0
Apr 4, 2005
#13
  • Apr 4, 2005
  • #13
shewitt said:
Im just going by what people have wrote on this board about 1.7 and gt40p's.
Click to expand...

I'm gonna take the risk. The 1.7's are easy to change back to 1.6's, and I can sell the 1.7's on eBay.
 
5

5.0alltheway

New Member
Mar 30, 2005
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carolina
Apr 4, 2005
#14
  • Apr 4, 2005
  • #14
im running 40ps ported polished,1.7s ,stock cam,mac headersw/a carb and 410s,this thing pulls very strong up to 6000,cant complain at all.
 
5

5.0alltheway

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carolina
Apr 4, 2005
#15
  • Apr 4, 2005
  • #15
im running 40ps ported polished,1.7s ,stock cam,mac headersw/a carb and 410s,this thing pulls very strong up to 6000,cant complain at all.oh yeah ,mine have been milled .040 w/o clearance probs
 

Mike86Stang

Advanced Member
Apr 11, 2000
10,296
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77
Red Lion, PA
Apr 4, 2005
#16
  • Apr 4, 2005
  • #16
FWIW I think the Gt-40p's would be the best choice of the bunch you posted....

Mike
 

94GT40

New Member
Mar 30, 2005
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Apr 5, 2005
#17
  • Apr 5, 2005
  • #17
5.0alltheway said:
im running 40ps ported polished,1.7s ,stock cam,mac headersw/a carb and 410s,this thing pulls very strong up to 6000,cant complain at all.oh yeah ,mine have been milled .040 w/o clearance probs
Click to expand...

Thanks for the reply... I'm headed to the post office to get a money order and sending off for the heads right now. Starting to get pretty stoked. I'm anxious get them on with the other stuff, drive it and get the dyno numbers.

I'm curious to see how the larger valves will affect performance compared to others with similar combos.
 
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