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

Getting My 302 Running Again

  • Thread starter Thread starter 68Blue302Coupe
  • Start date Start date Nov 28, 2009
6

68Blue302Coupe

New Member
Jul 30, 2005
74
0
0
Fairfax, VA
Nov 28, 2009
#1
  • Nov 28, 2009
  • #1
Hey All,

So I have been in the process of getting a 1971 302 running again after sitting for about 7 years in a garage. As far as I know, its running a stock cam, heads, and pistons/bore. I bough the engine off a friend's donor car years ago, and it was supposedly rebuilt, but in retrospect I have no idea if it really was or to what quality level. It is possible the cam may be non-stock, but I have no clue.

The engine has an old Holley Contender manifold, a 500 cfm Eddlebrock, high volume oil pump (plan to swap that out with a stock unit ASAP), Tri-Y headers, an old Jacobs electronic ignition, and standard distributer with a Pertronix Ignitor. I've changed the spark plugs, oil, and coolant too, of course, and put a on new intake gasket. I also just had to replace the harmonic balancer.

I recently fired it up for first time, ran it for a few minutes, notice a freeze plug and exhaust leak as well as a wobble in the original balancer, and shut it off. After repairing the leaks and changing the balancer, I started it up again the other night, ran it for a couple minutes, and shut it off.

So it has been only run for a few minutes after sitting for 7ish years.

My question is if I need to be doing anything different in trying to get this thing running again. I noticed that the engine runs rough, sounds rattley, and stumbles when I rev it. The carb is new, out of the box, and I have not made any adjustments to it. I have advanced the timing a little.

Should I just start it up and let it run for a good 20-30 minutes before messing with any tuning? Should I compression test first? What about adjusting the valves (never tackled that before).

I am also suspicious of the distributer. The 302 did not have one when I got it, so I picked one up at the local mega parts store, asked for one for a 1971 302 with a vaccum advance. But, I wonder if I got the right one, or if I should upgrade to something slightly better (just not too much $$!).

I aslo had to crimp the passenger side header to clear the bell housing--good that be causing excessive back pressure and making the engine run rough? Should switch to stock manifolds?

I would really appreciate any tips or suggestions. This forum has been a lifesaver with this car!!
 
2

2+2GT

10 Year Member
Apr 25, 2009
3,333
10
79
Southeastern Pennsylvania
Nov 29, 2009
#2
  • Nov 29, 2009
  • #2
an old Jacobs electronic ignition, and standard distributer with a Pertronix Ignitor.
Really? I've always used Pertronix as the whole ignition system.

My question is if I need to be doing anything different in trying to get this thing running again. I noticed that the engine runs rough, sounds rattley, and stumbles when I rev it. The carb is new, out of the box, and I have not made any adjustments to it. I have advanced the timing a little.

Should I just start it up and let it run for a good 20-30 minutes before messing with any tuning? Should I compression test first? What about adjusting the valves (never tackled that before).
Always a good idea, but kind of a pain with the stepped 71 valve stems.

I am also suspicious of the distributer. The 302 did not have one when I got it, so I picked one up at the local mega parts store, asked for one for a 1971 302 with a vaccum advance. But, I wonder if I got the right one, or if I should upgrade to something slightly better (just not too much $$!).
You already have upgraded, with the Pertronix. BUT- it is unlikely in the extreme that the advance curves are within limits, or even close. This could be done for a lot less than some exotic distributor, which itself would probably need adjusting.

I aslo had to crimp the passenger side header to clear the bell housing--good that be causing excessive back pressure and making the engine run rough? Should switch to stock manifolds?
If all you did was flatten the Tri-Y tube a little, you should be fine. Stock manifolds? Bite your tongue. You'd have to mash the tube to make it that bad, although I use the 289HP manifolds on my 289HP.

Just go through the usual tune-up adjustments, and get that distributor adjusted. If no one does it locally, I know a Mustang shop you can send it to.
 
You must log in or register to reply here.

Similar threads

L
95 gt engine vibration
  • lenzgt
  • May 11, 2026
  • 1994 - 1995 Specific Tech
Replies
6
Views
145
1994 - 1995 Specific Tech May 26, 2026
lenzgt
L
9
2012 Boss 302 help
  • 94blackvertgt
  • Aug 21, 2025
  • 2005 - 2014 S-197 Mustang -General/Talk-
Replies
1
Views
186
2005 - 2014 S-197 Mustang -General/Talk- Aug 21, 2025
Noobz347
S
Fox '87 GT can't get to stay running
  • spilly
  • Mar 29, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
27
Views
617
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Saturday at 9:59 AM
spilly
S
Hard to start when engine is cold
  • 86_Capri
  • Mar 11, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
32
Views
803
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Sunday at 2:39 PM
CAMTWO1070
M
Help! 2003 GT misfire when hot
  • Modular03
  • Feb 10, 2026
  • SN95 4.6L Mustang Tech
Replies
4
Views
320
SN95 4.6L Mustang Tech Feb 13, 2026
Mustang5L5
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?