At what point in cam size do you run into trouble with the nonadjustable rockers on a 289? I've seen the rocker arm kits to make them adjustable but I may not need them? I'm helping my wifes uncle build a 65 mushmule and even though I hate 65 mustangs with a passion, I still need to do it right.

I thought 289's had adjustable rockers just like our's only 1.6 ratio instead of 1.5 ratio.

Doesn't the 271hp/289 have solids that have to be adjusted like our solids do??

pdq67

I'm learning as I go and going on what I've heard. I haven't gotten deep enough to know if they are adjustable yet. The solid lift engine has adjustable rockers but I'm not sure about the hydraulics.

As I remember, the 289 and 302's had adjustable rockers on the Hyd's, that looked just like the sbc (ratio ?). I can't tell you at what cam size you run into problem, as I have only rebuilt stock Ford engines. That was over 25 years ago, or maybe more. I do remember some of the big block fords having the non-adjustable rockers, like the 352's? I always liked the sb ford's intake, the bolts go straight down. Dist's up front, always made it easy to drop. Never liked the oil pumps, had one fail on me.

Good luck,
Fred.

Where do you think the Vortec heads, intake bolt pattern came from??

None other then the Blue Oval!!

Tit for tat, I say!! They got our rocker and stud design AND we finally got their intake bolt pattern design!!

he, He!!

pdq67

IIRC the 289 rocker nuts have a relief on the bottom on the threads and tighten up against a shoulder on the stud or something. Looks like a Chevy setup but isn't really adjustable. .050 or .100 long pushrods are no big deal if the cam is big enough to have a smaller base circle, but you're going to be having some serious valve spring issues by then anyway. It's been too many years but I sort of recall getting better springs on these heads was a real PITA for some reason. You probably don't want to be putting much cam in an engine that small anyway. They have absolutely no low speed torque with a big cam, you'll have to get out and push to get it moving. smile.gif

Tom

Thanks for the info. The cam is a small, no name, RV/replacement cam and I feel sure that it would be a bolt in, I just need to be sure.

Over .500 lift then it's a possible problem.
Mild RV cam OK
I have a Ford guy right around the corner from me smile.gif

Thanks mr 4 speed.