A few questions about swapping heads

[thegreatjustino]

Some of you have followed my 351 upgrade debacle for the past five years. I'm obviously taking my sweet time on it these days, but am back on track. I've scrapped the last engine I was trying to use and have purchased a rebuilt 1995 351 with all paperwork from the machine shop included by the guy I got the engine from.

Being a 1995 engine, it is not a roller block. However, when it was rebuilt, it was upgraded to a conversion roller cam (Comp 35-412-8) as well as a set of roller rockers.

Before I bought this engine, I bought a set of AFR aluminum heads in anticipation of building the engine I wanted.

My first question is it worth the time and effort to swap out the 1995 Ford heads for the AFR ones? I believe the 1995 heads would be GT40s, but I'm not sure of that.

If I end up swapping the heads, do I need to go to the extent of removing the valve springs from the stock heads and swapping them over to the AFR heads? The AFR heads came assembled with springs, but I don't know if the spring rate is accurate or appropriate for the cam that was installed with the rebuild.

Would swapping the heads require a different length of push rods?

Pictures of both the Ford and AFR heads as they currently sit:

 

[Crush]

Your 95 heads are e4te heads. They flow pretty good but not like a gt40 head. That 95 block should have been a roller block. Everything from 94 up is a roller and 93's are drilled for rollers. I have a 94 351 and it is a roller. The afr's should flow better than the e4te's but its gonna depend on he cam choice you have as to how well they work together. Remember it is a package and all components must work well together. They will work together but the key is work well together. Good luck and maybe someone with a little more techincal information will chime in too

 

[Viperwolf1]

Your 95 heads are e4te heads. They flow pretty good but not like a gt40 head. That 95 block should have been a roller block. Everything from 94 up is a roller and 93's are drilled for rollers. I have a 94 351 and it is a roller. The afr's should flow better than the e4te's but its gonna depend on he cam choice you have as to how well they work together. Remember it is a package and all components must work well together. They will work together but the key is work well together. Good luck and maybe someone with a little more techincal information will chime in too

The stock heads on a late 351w are E7TEs. Ok for stock heads but not as good as GT40s. The AFRs will give you a good torque boost above 3,000 rpm with all else being the same.

You will need to enlarge the holes for the 1/2" head bolts on the 351w. The AFR springs should be ok with that mild cam. You will probably have to measure for pushrods with the odd combination of cam/lifters/heads/etc.

 

[bronconut73]

Do the AFR's.

They will be far superior to the oem head.

Expect to need custom length push rods....but maybe not.
Summit and Jegs have adjustable length push rods to get your exact length, then you can often just give Summit or Jegs a call and they will likely have some on the shelf, no biggie.

 

[NYLES]

AFRs you know you got em,. What size are they I run 58cc with 165 runners on my 302.....I love em I Was running P heads AFR a world of diff

 

[thegreatjustino]

The heads are AFR SBF 185cc Race Strip CNC Aluminum Cylinder Heads 58cc chambers Stud Mount complete w/parts (AFR-1388)

 

[NYLES]

The heads are AFR SBF 185cc Race Strip CNC Aluminum Cylinder Heads 58cc chambers Stud Mount complete w/parts (AFR-1388)

Hell yea! It'll come alive with the right cam.

 

[Nickm1024cobra]

AFR all day long

 

[77RHINO]

I built my 351 roller last year, and went with ford racing GT40X aluminum heads that had a 64cc chamber/178cc runner to get my CR back where it needed to be, somewhere around 9.5 or so, using flat top pistons with valve reliefs. Heads came with springs able to handle the lift of my cam, XE266HR-12. Also went with pedestal mount roller rockers, and I was able to use factory size hardened pushrods. Rguest on here has built a few and I followed one of his builds nearly to a T, except for maybe the heads. Ive been super happy with mine, good luck!

 

[Broncobowsher]

So a choice of stock cast iron heads or aftermarket aluminum heads? What's the question again? Why even consider the cast iron.

You want to run the AFRs.

 

[sykanr0ng]

Even if it came with a flat tappet cam (many did) it would be a roller block if it is still the 1995 block you started with.

There would be no reason to use a conversion cam.

 

[NYLES]

Just have your springs checked to be on the "for sure good to go side".

 

[thegreatjustino]

Even if it came with a flat tappet cam (many did) it would be a roller block if it is still the 1995 block you started with.

There would be no reason to use a conversion cam.

I am simply going by the receipt of the machine shop that states it's a 1995 351W. As for the conversion cam, when I purchased the engine, I also got a box full of the empty boxes of parts that were used when the engine was put together. The cam box is from the conversion cam listed in my first post. The receipt from the machine shop lists all the machine work and assembly to a short block. It does not include the cost of the cam itself or the rockers. Based on this, it's my assumption that whoever had the machine work done was the guy who completed the engine and selected the cam and rockers. No clue why he would have used the conversion cam either if the '95 block was a roller to begin with.

 

[rguest3]

What is the date stamp on the Block? Has it been confirmed a F4TE block? (right where the starter would mount) Sounds like it is ready for the Roller Cam as is.

The 185 AFR heads are no doubt one of the best heads for the 351w. I had the 351w and the 185s AFR is my Green 77 with a Comp Cam XE266HR-12 cam. VERY strong motor with plenty of RPMs. Slight lope at idle and sounded great! But it needed some RPMs.

My next build will have the 351w, 165 AFR heads and a Comp Cam XE258HR-12. I have build this same motor before with great results and tons of torque down low just off idle. Still plenty of RPMs for a Bronco.

My Roller Cam recommendations for the Bronco would be:

Comp Cam - XE258HR-12 - 208, 216 Duration and .533, .544 Lift
Comp Cam - XE264HR-14 - 212, 218 Duration and .512, .512 Lift

 

[thegreatjustino]

Just went and looked at the casting number.

F4TE-6015-AA-14

From what you're implying, this is in fact a roller block?

 

[Broncobowsher]

Correct, it is a roller block.