• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

351 heads

  • Thread starter Thread starter f8tlfiveo
  • Start date Start date Dec 20, 2011

f8tlfiveo

My wife likes my spool and blow-off valve.
Aug 8, 2007
1,585
102
64
Lancaster, PA
Dec 20, 2011
#1
  • Dec 20, 2011
  • #1
I am tossing around the idea of doing a 351 swap.. I have gt40p's on my 302 at the moment. Would these flow any better than a stock 351 head?Are there any decent ford production heads to put on a 351? I have searched and not been able to find much. I know putting 302 heads on a 351 will give you 302 power, just wasn't sure how good a stock 351 head would flow. If they are going to flow about the same I can just find a shortblock and use gt40p's for now.
 

Jason 302

10 Year Member
Aug 9, 2003
685
71
68
Newark, Ohio
Dec 20, 2011
#2
  • Dec 20, 2011
  • #2
I feel like a 351w with GT-40P heads won't be anything more than a stump puller that belongs in a truck. Not saying it wouldn't run well, just saying those extra cubes need to breath.

Personally I would save my pennies for a while and invest in some AFR 185's....then hang on
 

f8tlfiveo

My wife likes my spool and blow-off valve.
Aug 8, 2007
1,585
102
64
Lancaster, PA
Dec 20, 2011
#3
  • Dec 20, 2011
  • #3
Yeah.. I didn't really think it would be a performance upgrade.. I am going to turbo my car, so I figured I would start with a 351 block for more strength rather than buying a aftermarket 302 block.. Plus you get a couple extra cubes out of it.
 

srtthis

the guy doing it does every local racers rear end
15 Year Member
Jul 3, 2009
5,129
1,666
204
Maryland
Dec 20, 2011
#4
  • Dec 20, 2011
  • #4
if i remember right the 351 heads flow ok but are somewhere around 72CC so they they dont make a lot of compression. which is what your looking for with a turbo
 

f8tlfiveo

My wife likes my spool and blow-off valve.
Aug 8, 2007
1,585
102
64
Lancaster, PA
Dec 20, 2011
#5
  • Dec 20, 2011
  • #5
Yeah definitely wanna keep it on the lower side..
 

VibrantRedGT

"STANGNET'S PENGUIN SMACKER"
15 Year Member
Nov 29, 1999
14,679
424
154
Boca Raton, Florida
Dec 20, 2011
#6
  • Dec 20, 2011
  • #6
GT40p heads are ok for a 302 not a very good choice for a 351. Like mentioned AFR 185's are ideal, had these on my 347, just an excellent head. Look into a custom cam and 351 intake from TFS. With a turbo all this will really make some ponies.
 

f8tlfiveo

My wife likes my spool and blow-off valve.
Aug 8, 2007
1,585
102
64
Lancaster, PA
Dec 20, 2011
#7
  • Dec 20, 2011
  • #7
Is it easier to buy a newer roller motor rather than converting a old one to a roller?
 

CarMichael Angelo

my rearend will smell so minty fresh,
15 Year Member
Nov 29, 1999
10,641
8,909
234
Birmingham, al
Dec 20, 2011
#8
  • Dec 20, 2011
  • #8
You have to remember that stock 351w heads just plain suck. The last time I paid attention to stock 351w valve sizing, it was 1.85/1.54 I./E. Respectively.The exhaust port is tiny, shaped poorly, and full of cast iron warts and bumps. that was on a C9 or D0 "4bbl" head." later model smog heads were even worse.
I would imagine that the valve size has not increased since then. A gt40 head has what? A 1.9/1.6 valve size? Although that sounds like a stock 351 w head,. The port should be a little better though, and as a rusult should be a little better. As opposed to running vs not running ( since you have those heads already) I'd use what I had until I could afford a better head.
 

f8tlfiveo

My wife likes my spool and blow-off valve.
Aug 8, 2007
1,585
102
64
Lancaster, PA
Dec 20, 2011
#9
  • Dec 20, 2011
  • #9
My gt40p heads are 1.84 intake and 1.54 exhaust. I bought them redone with bigger exhaust valves. I would think that these would be better than a stock 351 head. And they only have about 2000 miles on them..can I run these heads on a non roller motor? I think I read a small base circle cam is needed.
 

f8tlfiveo

My wife likes my spool and blow-off valve.
Aug 8, 2007
1,585
102
64
Lancaster, PA
Dec 20, 2011
#10
  • Dec 20, 2011
  • #10
Is there a "budget head" that can be used without spending 1000$+ on a set of heads?
 

Gearbanger 101

Straight Outta Locash
20+ Year Stangneter
Aug 10, 2002
9,457
1,377
234
Ontario, Canada
Dec 21, 2011
#11
  • Dec 21, 2011
  • #11
Ported GT40's are't going to be ideal, but the'll get the job done. Remember, these were the same heads found on the '95 Cobra R and it made 300hp with very little effort.
 

f8tlfiveo

My wife likes my spool and blow-off valve.
Aug 8, 2007
1,585
102
64
Lancaster, PA
Dec 21, 2011
#12
  • Dec 21, 2011
  • #12
Gearbanger 101 said:
Ported GT40's are't going to be ideal, but the'll get the job done. Remember, these were the same heads found on the '95 Cobra R and it made 300hp with very little effort.
Click to expand...
so if I ported the gt40p's I should be ok until I can get better heads.
 

srtthis

the guy doing it does every local racers rear end
15 Year Member
Jul 3, 2009
5,129
1,666
204
Maryland
Dec 21, 2011
#13
  • Dec 21, 2011
  • #13
Gearbanger 101 said:
Ported GT40's are't going to be ideal, but the'll get the job done. Remember, these were the same heads found on the '95 Cobra R and it made 300hp with very little effort.
Click to expand...

same heads as a 93-95 lightning also
 
You must log in or register to reply here.

Similar threads

T
New Guy from Southeast Missouri
  • tcooke11
  • Jan 10, 2026
  • The Welcome Wagon
Replies
1
Views
246
The Welcome Wagon Jan 17, 2026
TomcatPC
3
Fox 351 dipstick showing overfull?
  • 387lx
  • Feb 9, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
1
Views
121
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Feb 9, 2026
Noobz347
9
Engine Donor '00 Mountaineer meet '91 Fox
  • 91firecracker
  • May 11, 2026
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
41
Views
561
Fox 5.0 Mustang Tech May 28, 2026
91firecracker
9
9
Forced Induction Prepping for supercharger on non-stock build
  • 91fox427
  • Nov 25, 2025
  • Fox 5.0 Mustang Tech
Replies
7
Views
372
Fox 5.0 Mustang Tech Jan 5, 2026
Qtrhrse23
Q
Engine Suggestions on an engine rebuild. Stock cam/GT40Ps or aftermarket on both for a fun weekend driver?
  • MadSquirrelTech
  • Apr 28, 2026
  • Fox 5.0 Mustang Tech
  • 2
Replies
23
Views
604
Fox 5.0 Mustang Tech May 7, 2026
MadSquirrelTech
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?