• Mustang Forums
  • 1974 - 1978 Mustang II Talk & Tech

Need advice on rockers, rail type

  • Thread starter Thread starter THE78II
  • Start date Start date Jul 12, 2006
T

THE78II

Founding Member
Feb 19, 2001
73
0
6
Jul 12, 2006
#1
  • Jul 12, 2006
  • #1
I have a '77 with rail rockers, and I'm buying a set of reconditioned heads. Right now, I have a choice of '77, rail type, and using Comp Cams roller rockers, or '78, fulcrum guided (stamped steel), with standard rockers.
Which way should I go with this? Are the '77 rails with rollers better than '78 with stock non rollers?
I've had rail rockers, and no problems with them, but I have heard they can jump the valve tip. I don't race, and never ran across this problem, or heard of anyone having trouble with them, other than wear, but that would be very high mileage.
Any opinions? Thanks a lot.
 

itsaMustangtoo

New Member
Apr 2, 2005
292
0
0
Carlisle,Pa
Jul 17, 2006
#2
  • Jul 17, 2006
  • #2
The difference would be CC. You need to check the casting numbers on the head. You do not want to go from say, a 63cc head to a 69 cc head. This would lower your performance. So your question is more than rocker arm type.
 

Dano78

Founding Member
Nov 1, 1999
2,633
1
47
Vancouver, WA
Aug 30, 2006
#3
  • Aug 30, 2006
  • #3
IIRC both the '77 and '78 SFB heads are 69cc. I, myself, prefer the rail rockers over those goofy bolt-down '78 stamped rockers. Have had a set on my Ranchero for years and as a 16 year old I beat the snot out of that 302 and never had a rocker pop off. And that was witht he Rpms floating in the 5500 range.
 
M

Mustangj

Founding Member
Apr 22, 2001
1,228
2
0
Guelph, Ontario, Canada
Sep 25, 2006
#4
  • Sep 25, 2006
  • #4
I have 1975 heads with rail type rockers. I have comp cams magnum roller rockers on my car. My car is a week-end toy and it is beaten with out mercy 5500RPM shifts (100hp nitrous kit too) on stock parts store rebuilt heads. I have never had any valvetrain failures. Oil pump, pistons, rods, gaskets and transmissions are another story though
 
M

Mustangj

Founding Member
Apr 22, 2001
1,228
2
0
Guelph, Ontario, Canada
Sep 25, 2006
#5
  • Sep 25, 2006
  • #5
Oh, I almost forgot My heads have an in-expensive kit from Comp that makes the rockers adjustable. It works very well also.
 
You must log in or register to reply here.

Similar threads

F
Getting my old autocrosser running again
  • flightops
  • Aug 28, 2025
  • The Welcome Wagon
Replies
6
Views
262
The Welcome Wagon Aug 28, 2025
Noobz347
L
Engine Need help diagnosing 2 dead cylinders
  • lvgnmz
  • Feb 13, 2025
  • Fox 5.0 Mustang Tech
Replies
3
Views
445
Fox 5.0 Mustang Tech Feb 13, 2025
Mustang5L5
3
Eight inches is enough for me...
  • 351MooseStang
  • Nov 27, 2025
  • 1974 - 1978 Mustang II Talk & Tech
Replies
5
Views
554
1974 - 1978 Mustang II Talk & Tech Mar 2, 2026
Bullitt347
Engine Valve and or rocker noise .....new to this but dont mind getting my hands dirty.
  • mustang matt 1993
  • Jun 29, 2024
  • Fox 5.0 Mustang Tech
Replies
16
Views
2K
Fox 5.0 Mustang Tech Jul 1, 2024
rednotch
S
Requesting Guidance for 306 motor swap - Fuel? - SD? MAF?
  • So_Flo
  • Jul 26, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
32
Views
2K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 4, 2026
Mcmahst
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1974 - 1978 Mustang II Talk & 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?