• Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific Tech

Boss 302 in a 66

  • Thread starter Thread starter Skid Mark
  • Start date Start date Oct 18, 2004
S

Skid Mark

New Member
Oct 18, 2004
3
0
0
Oct 18, 2004
#1
  • Oct 18, 2004
  • #1
Bought a 66 fastback 6 mths ago. It has a Boss 302 engine, 4 speed trans unknown. Previous owner had motor built and installed 10 years ago and started having kids. So the car sat. I have been working on my resto plan. I want reliability and plan on selling the motor and trans.Motor LOOKS bad but runs strong. Do I sell motor in the car or pull motor to sell?
Thanks
 
D

D.Hearne

New Member
Sep 29, 2000
11,730
6
0
south louisiana
Oct 18, 2004
#2
  • Oct 18, 2004
  • #2
What makes you think it's a Boss 302 ?
 
S

Skid Mark

New Member
Oct 18, 2004
3
0
0
Oct 18, 2004
#3
  • Oct 18, 2004
  • #3
Casting numbers on block match a 69 Boss 302
 
D

D.Hearne

New Member
Sep 29, 2000
11,730
6
0
south louisiana
Oct 18, 2004
#4
  • Oct 18, 2004
  • #4
Does it have: Cleveland style heads (8 valve cover bolts per head), aluminum high rise dual plane intake, dual point dist., screw in core plugs ( not press in freeze plugs ) ?
 
D

D.Hearne

New Member
Sep 29, 2000
11,730
6
0
south louisiana
Oct 18, 2004
#5
  • Oct 18, 2004
  • #5
If it does have the above, why would you want to get rid of it?
 

MustangMatt1966

New Member
Mar 11, 2004
1,004
1
0
Orlando Fl.
Oct 18, 2004
#6
  • Oct 18, 2004
  • #6
i would rebuild that sucker, its worth a good chunk of money
 
S

Skid Mark

New Member
Oct 18, 2004
3
0
0
Oct 18, 2004
#7
  • Oct 18, 2004
  • #7
Yes to all of the above.
My thoughts are:
- Header fit. The headers that are on now come forward and run back below the motor
- Leaded fuel
- Better performance and reliability from modern motor
 

66P51GT

New Member
Nov 7, 2003
721
1
0
Cerritos, CA
Oct 18, 2004
#8
  • Oct 18, 2004
  • #8
Skid Mark said:
My thoughts are:
- Header fit. The headers that are on now come forward and run back below the motor
- Leaded fuel
- Better performance and reliability from modern motor
Click to expand...
Sounds like you could have a set of custom headers. Check the diameter of the primary exhaust tubes at the heads. If they are in the 1 7/8" range, they would cost you over a grand to replace. If they are this large, they are for High RPM operation. You will give up quite a bit of torque below 3500 RPM.

If you plan putting 20-30k miles on the engine, have the heads refitted with hardened valve seats to support unleaded fuel. Otherwise if it is a weekend warrior running race gas, don't worry about it.

Few small block Fords can compete with the revving capabilities of Boss. Performance wise, these were stout platforms for making 500+ HP at high RPMs.

Another plus for the Boss is the use of longer rods. They use the same length rod as the 289 (5.155 vs 5.090) and use a shorter piston height (1.529 vs 1.605) to compensate for the additional rod length. The rods also come with a larger rod bolts than the stock 289 or 302 rods. The theory behind the long rod is it allows the piston to stay at TDC and BDC for a fraction longer to improve breating and scavenging. It also increases the piston speed in mid stroke which gives the Boss an edge in higher RPMs vs a standard rod 302.

I'm using the same geometry in the motor I'm currently building (see sig). However, I don't have the stronger block nor the forged crank. 2 advantages I wish I had and could afford.

Keep the Boss. Keep it a solid lifter and build it to rev. The engine is a natural in an open-track or autocross car.
 
You must log in or register to reply here.

Similar threads

T
Engine 1970 302 boss block
  • TOM B
  • Jan 4, 2025
  • Classic Mustang Specific Tech
Replies
3
Views
420
Classic Mustang Specific Tech Jan 14, 2025
lqbbe
L
D
66 Coupe Progress Thread
  • DTCRAWLEY
  • Apr 19, 2026
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • 2 3
Replies
43
Views
981
1965 - 1973 Classic Mustangs -General/Talk- Jun 17, 2026
DTCRAWLEY
D
E
4.6l auto to 5.4l 6 speed
  • EastanF5
  • Jan 22, 2026
  • SN95 4.6L Mustang Tech
Replies
0
Views
181
SN95 4.6L Mustang Tech Jan 22, 2026
EastanF5
E
J
Help Figuring Motor Choice(Possible future turbo)?
  • jaygee15
  • Dec 14, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
13
Views
623
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 3, 2026
Jarhead67
J
Progress Thread Progress Thread- From6to8's 95 GT/Saleen Supercharged 331 install
  • from6to8
  • Mar 22, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
24
Views
890
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- May 6, 2026
from6to8
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific 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?