Ah ok, I mistook what was said then. I was talking about aftermarket heads are all adjustable stud mounts but some will accept non adjustable pedestal mounts as well. Thought you were expanding on that. I don't know about oem factory heads, all I know about them is they are non adjustable pedestal mount and then there is the adjustable stud mount. Don't have a ford with a stud mount rockers only pedestal and shaft mounted.

 

Most all Fords with the stud mounted rockers are non-adjustable also. Yes, there were a few rare oddballs but the ones most people will run into will be the ones you run down tight and then that's it. They make kits that you can use to convert them to adjustable. Usually they were a very tall nut, and then a set screw screws into the top of the nut. You adjust the tall nut till your lash is correct, then while you hold the nut with a wrench, you take a allen wrench and tighten the set screw down till it hits the top of the stud and jambs the nut tight.

 

Interesting, never saw that setup it sounds like a polylock nut found on roller rockers. Guess I am lucky to be going with aftermarket AFR heads for my build even though some think the AFR 165`s are over kill for a 306 displacement but screw it I want aluminum and I want new not some rebuilt factory stuff.

 

The SBF's with adjustable lash were not rare or oddball most 4BBL 289's used mech lifters. And I would not exactly call the 4BBL 289 a rare or oddball engine.
Ford used a self locking distorted thread locknuts as the lock for mech lash on the non boss SBF's with screw in studs instead of press in studs.

You can adapt and stud mounted rocker to fully adjustable by installing a spacer between the fulcrum ball and the nut and using a lock nut. This will of course require changing the push rod length...

Below is a pic of the lock nuts Franklin was referring too.

 

This article claims only 13,000 K code mustangs were built from 64 thru 67, out of 1.7 million. I am understanding the K-code would have gotten that solid lifter engine. I didn't do any research on any other Fords, but they probably put that engine in some other body style also. But I bet there were not that many made.

https://www.hemmings.com/blog/articl...ng-k-code-289/

 

Just over 25,000 K code 289's were made in total. That is more than Mercedes sold vehicles total in Canada any year prior to 2010. So that is like saying any Mercedes of any specific year prior to 2010 in Canada is rare and an oddball. Rare and odd ball is the D code 289...

 

Well I was putting in new valve stem seals and cleaning/lapping the valves and it turns out the head is cracked between the intake and exhaust valve on cylinder 5. I'm going to need new heads.

If I can find a set of GT40 heads what other parts will I need to grab? Will I need the pushrods from the Explorer or can I re-use mine from the '92 F150, or will I just need to measure to find out? Will the stock springs on Explorer head work?

 

That's why I hate to get used parts vs a rebuilt part.

If you have roller rockers already you should be fine running the pushrods you have as they should be around the same 6.2" length vs the 6.7" length Ive seen for flat tappet lifters. If you are changing the rockers out for a different ratio then you be best to get a pushrod length checker like I got and find what you need.

I might be able to get by with stock 6.2" or one size up but I am not running much stock of anything on my build unlike your use of factory GT40 heads and pedestal mount rockers.

 

This '92 has flat tappet cam and hydraulic lifters, solid rockers. Just get a length checker going to be my best bet?

 

I would to be safe. I forgot this is a 351W so the pushrod length will be different than what I stated as those are for a 302 with a shorter deck height than the 351w.

But I would get the pushrod length checker like I did and maybe you might want to invest in some checking springs like below.

https://www.summitracing.com/parts/cca-4758-2

Get a pair for a few bucks and all you do is remove a intake and exhaust valve spring and you can easily open and close the valves with your intended lifter. Some people Ive read had issues with lifters trying to collapse rotating the engine over by hand which was effecting their valve train movement.

Another thing is put alittle black sharpie mark on the tip of the valve stem then rotate engine over a couple cycles by hand then check the pattern. I cant remember when you length and shorten the push rod off the top of my head but there is a lot of reference material out there.

 

I remember seeing something like this once. I think it was that you were trying to center the wear pattern. If it was too far one way it meant longer pushrods and too far the other meant shorter. Don't remember which bit I'd think a checker would be easiest.

Thanks for your help.

 

Yep that's what the push rod length checker is for to find the right length pushrod to center your valve train over the valve stem.

The soft valve springs for checking makes it easier so you don't have to worry about the lifter collapsing on you. Also will work great in my book as I have to clay the pistons as I don't know what pistons BluePrint uses on their 306 short block but AFR has recommendations for how much clearance you have to have between the 1.90" and 1.60" valves. So for me the softer springs will serve dual purpose for me.

 

Stock 351W flat tappet pushords for fulcrum rockers will be what you need with the Gt40 heads on flat tappet cam.

https://www.rockauto.com/en/catalog/...,push+rod,5648

 

The rocker arm pedestals are not taller/shorter on the GT40 heads than the earlier cast iron heads from Ford?

I thought there might have been a difference but if not that would save him money and time from having to do checking to find the proper length.

I got a set of some Comp Cams 6.70" length pushrods at work came out of a 302 that some kid blew up by thinking it was a hotrod when all it had on it was just a pair of 351W heads on it lol. I kept them to save myself money but forgot his was a flat tappet engine where mine is going to be a roller.

At least I got some useable parts that I can sell/trade one day to recoup some of what I spent.

 

On all the standard production pedestal mount heads the installed height of the fulcrums are the same. This is in part what makes the GT40 swap so nice as it is literally a bolt on as you only need to change the head actual and you can reuse all the ancillary bits.