258 DOG - JeepForum.com
LinkBack Thread Tools
post #1 of 3 Old 12-01-2001, 08:36 PM Thread Starter
jerk with a jeep
Registered User
Join Date: Dec 2001
Location: Bonney Lake Wa.
Posts: 34
258 DOG

I have an 89 YJ that is slow. It does have an automatic trans which doesn't help. Does any one know if a 4.0 head will fit the 258 block? I am going to install headers, juice box TFI ignition upgrade and after market carb and manifold. Which would be the best way to go,clifford intake and holley carb or weber and the stock manifold? I need to get more power out of this thing!

jerk with a jeep is offline  
Sponsored Links
post #2 of 3 Old 12-01-2001, 10:42 PM
Registered User
Join Date: Mar 2001
Location: Michigan
Posts: 471
What are your rpm's like? If you're having problems getting any high rpm's, then you could have a plugged catalytic converter. My 89' yj w/4.2 had absolutely no power and was really a dog. I couldn't even get 2800 rpm's when I first noticed I was having problems. By the time I figured out what was going on, all I could get was 1200 rpm's and I couldn't even climb a slight hill going down a paved road.

89' YJ - 4.2 - NV4500 - NP231w/sye - 1" Body Lift - 2 1/2" Rancho Suspension Lift - 31" Firestone MTR - AR Outlaw II - Tomken Bumpers F & R - Warn 8000 front - Warn 6000 rec. mount rear - FlowFit Seats - Tom Woods Rear & Custom 2" front driveshafts
FLHT_FXRS_YJ is offline  
post #3 of 3 Old 12-01-2001, 11:48 PM Thread Starter
jerk with a jeep
Registered User
Join Date: Dec 2001
Location: Bonney Lake Wa.
Posts: 34
Are you into harleys? Iam building a soft tail,a realy fat soft tail.
I had not thought about the cat converter, I'll check it. I,ve had other 4.0,s and 258,s and they ran realy well. It seems realy odd that this one doesn,t. Thank you for the info. Let know about the bikes.
jerk with a jeep is offline  

Quick Reply

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome