5.0 heads on a 5.8

just wondering if anyone has ever drilled the head bolt holes themselves or is this something you would leave to the machine shop.... Thanks

No reason you can't do it with a drill press and a good vise/clamp system

dfree383 wrote:No reason you can't do it with a drill press and a good vise/clamp system

X2 have done this personally ! Worked great

plowboy34 wrote:just wondering if anyone has ever drilled the head bolt holes themselves or is this something you would leave to the machine shop.... Thanks

What head are you going to use? If it's a GT40 , it's already drilled. If not you might be better using the 351 head.

yes it's GT40, I never checked them was told I would have to drill them. I hope your right gt350hr will be checking when get home

plowboy34 wrote:yes it's GT40, I never checked them was told I would have to drill them. I hope your right gt350hr will be checking when get home

From those I have observed ... GT40 - no; GT40P - yes.

I've done it with a Makita drill when I was a teenager.  

That motor is still running in an old dudes farm truck to this day just as i built it.

The gt40 heads that I did and put on a 351w had to be drilled in order to be bolted to the 351w .I can not say for the gt40p heads as I haven't put a set on a 351w yet. I do have a set of GT40P heads I can check.

whitefield wrote:The gt40 heads that I did and put on a 351w had to be drilled in order to be bolted to the 351w .I can not say for the gt40p heads as I haven't put a set on a 351w yet. I do have a set of GT40P heads I can check.

I have probably seen hundreds of the O.E.M. production GT40 heads and none of them were produced for use with the smaller head bolt holes for regular 7/16" head bolts.

The GT40 heads were production O.E.M. heads on a 351 Windsor engine in a 1993 Mustang Cobra ... they were never offered on a 302 engine in O.E.M. production.  
Ford Motorsport SVO did offer them in their "Street Legal" 5.0 kits in the late 1990's, (part number M-6049-L303), and I put quite a few of those together. The L303 heads we had were all for larger head bolts but, the "torque to yield" 7/16" head bolts had a large washered head and didn't need "step" washers.
Maybe ... by chance ... some came down the line with smaller head bolt holes but, I never saw one.

There is also a marine GT40 head which is not the same casting. The exhaust ports are really, REALLY tiny inside.
I have about 20 pair of those heads right now with stainless valves installed; I will have to check the head bolt hole diameter of those.

The GT40P heads are the other way around as they were never offered on any 351 Windsor engines but, were production O.E.M. heads on 90's Explorer type vehicles with a 5.0 engine.

The explorer DID use a gt40 NON p head up till 1999 then they made the swap to gt40p ALL small head bolt deals

gmsmkr wrote:The explorer DID use a gt40 NON p head up till 1999 then they made the swap to gt40p ALL small head bolt deals

I may be wrong but, I doubt it.
1996 was the first year a 5.0 V8 was offered in that Explorer / Mountaineer and that was only with the XLT package; IF they had small diameter head bolt holes, they were not the same "bar" head castings as the GT40 Mustang Cobra engine.
The GT40P head production began with the 1997 model year and 2001 was the last year Ford put a pushrod engine in any production vehicle.

The gt 40 explorer/mountaineer had a 3 bar marking with casting F1ZE-AA which was until 1997 in 1998 there was still some gt40 heads on them in 1999 they where all gt40p heads 4 bar marking

Which you are correct they are not the same casting numbers as the lighting and cobra

I will say that I agree with both Randy and Mike but , Ford as well as other manufacturers did some last second ( sarcasm) changes and anything is possible . I just know for a fact that the Non P GT40 heads that I bolted on the 74 351w I built had to be drilled .

Which heads were on the 351W in the 1st generation Lightning F150s?

Lem Evans wrote:Which heads were on the 351W in the 1st generation Lightning F150s?

Regular GT40

dfree383 wrote:

Lem Evans wrote:Which heads were on the 351W in the 1st generation Lightning F150s?

Regular GT40

So, they would have to be for 1/2" bolts then?

These heads are the F3ZE casting (which have 7/16 head bolt holes) which a book I have says they came on the 93 Cobra's. The F4ZE casting is on 94-95 Cobra's, and the F1ZE casting was on the Explorers/Mountaineers.

plowboy34 wrote:These heads are the F3ZE casting (which have 7/16 head bolt holes) which a book I have says they came on the 93 Cobra's. The F4ZE casting is on 94-95 Cobra's, and the F1ZE casting was on the Explorers/Mountaineers.

Your book is not correct ... ALL the 93 SVT Cobra R Mustangs were 351 Windsor engines; (they have 1/2" head bolts).
They may have offered a hopped-up version of the GT and put a Cobra nameplate on it which would have been a 5.0L engine. I will have to check if those engines had GT40 heads, They did have the Crane 1.7 Rocker arms and tubular intake manifold.

rmcomprandy wrote:

plowboy34 wrote:These heads are the F3ZE casting (which have 7/16 head bolt holes) which a book I have says they came on the 93 Cobra's. The F4ZE casting is on 94-95 Cobra's, and the F1ZE casting was on the Explorers/Mountaineers.

Your book is wrong ... ALL the 93 Mustang Cobras were 351 Windsor engines; (they have 1/2" head bolts).

X2. ALL F3ZE casting had 1/2 head bolts

gmsmkr wrote:

X2.  ALL  F3ZE casting had 1/2 head bolts

I will check the archives tomorrow. The Mustangs in GT form had a 5.0L but, the 93 Cobra R's had 351 Windsor engines.
There may have been a GT upgrade which probably was badged as Cobra.  I know the GT upgrade came with the Crane 1.7/1 rocker arms and tubular intake manifold but, I don't think it had GT40 heads; but, maybe.

Those records will show part numbers not casting numbers so, I will have to verify a lot of it.

From my personal experience working in the ford dealer in 1992 and the 93 model cobra R were all equipt with 5.0 gt40 heads 24lb injector 1.7 crane roller rockers with ford part number cast in them recalibrate computer the transmissions were also different than the standard tremec/ t5 as well as clutch. There were a lot more differences in the cobra and the GT.

1995 was the first year for the 5.8 GT40 headed cobra R mustang.
As I stated before there are always exceptions as manufacturers have always done last second changes on any vehicle.

My observation is not book or enter net it is what came off the truck from ford to the dealer I worked in.

Lem Evans wrote:Which heads were on the 351W in the 1st generation Lightning F150s?

That would be three line GT40s

I've taken apart several 5.0s with factory stepped under head bolts.

The first thing I did this morning was come in here and look through the archives for information. It has been a long time since I used a MicroFish.

Anyway ... I've got to eat a lot of what I said.
There were over 4,900 Cobras sold in 1993 and just over 100 Cobra R's sold in 1993.
In that year the 351 Cobra R was strictly an option when ordering a Cobra Mustang.

The engine in the 1993 Cobra was a 5.0L with GT40 heads, (with especially milled deck surfaces to get down to 62cc's), 1.7/1 Crane rocker arms, tubular intake manifold; F3ZZ-9424-C upper & F3ZZ-9424-D lower, 24lb fuel injectors  with higher flow 70mm MAF meter calibrated for those injectors, shorty tubular headers, and had a different camshaft installed with less overlap in order to pass EPA emission standards; p/n F3ZE-6250-CA. It even came with a 14% under-drive, smaller crankshaft pulley.
The Cobra R "optional" package had the 351 Windsor engine which later in 1995 became a production engine without needing the option to get it.

At Ford Motorsport we sold the engine parts package to make a GT, (or any car with Mass-Air injection if you wanted), to have that engine package, (without the camshaft), and in that package was a special head bolt kit with stepped washers for the larger head bolt holes p/n M-6065-C289.  
All service and replacement GT40 heads came without the extra milling and with the larger bolt holes however, the O.E.M. production heads for those 5.0L engines may indeed have had the smaller 7/16" bolt holes.

I didn't realize I was gonna start such a conversation with my question as can I drill my own bolt holes or leave it to a machine shop......

Anyways not trying to make anyone mad but here are the facts on these heads as I have laid my own eyes to. They are F3ZE, 3 bar, GT heads, a 1/2" bolt will not go through holes and a 7/16" bolt will. To make sure I had correct size bolts I got out my caliper and checked them. I also checked the head bolts the guy gave me when I purchased the heads and they are 7/16". I also set it right on 1/2" and it definitely is to big to fit in holes. Again not trying to anger anyone just the facts on these heads.