Vintage Mustang Forums banner

Cobra rocker arms?

4K views 10 replies 6 participants last post by  Flade 
#1 ·
Anyone have experience with the Ford Cobra rocker arms F3ZE-6529-AB? They are 1.7 ratio. I have a set of GT40 heads for my 68 289. Wondering if these pedestal rockers are a good match for this set up.
 
#3 ·
Yes. I ran that exact setup on my now gone 89 Mustang. Stock GT40 heads with the stock 89 cam. Louder then stock rockers, sounded like a sewing machine. But I got 235RWHP through the AOD which is good considering usually those cars get 190RWHP stock.
 
#4 ·
Thanks, I am planning to use these to replace the anemic 2V heads on my 289. Add a mold cam , Tri y headers, dual exhaust and an Edelbrock intake should warm it up a little
 
#9 ·
I have the 68 289 2v heads that already have 63CC chambers and crappy compression. How are the GT40 heads different from the GT40P heads many people have been using? I have 66 heards that I could use but figured the GT40 heads would flow better
 
#8 ·
The Cobra rockers are basically Crane Energizer arms. I have old Energizer 1.6 arms on my 347" these are pretty silent. The have to be something in the combo of parts, that trigger the noise and amplifies it, when some people are having loud noise. I'm sure that just the aluminium vs. steel parts will make a difference in how any sound from the valvetrain are transmitted. Maybe some manufacturing tolerances also make some set of theses arms more noisy that others.
 
#11 ·
Thanks for the detailed answer. I knew about the plug angle & headers but didn't realize the combustion chamber was sized differently. Shame since he GT40 heads are in immaculate condition. I may just put them on my 95 instead of saving up for Aluminum heads
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top