Cyl head swap / update

[MattSinger]

Over the winter, I am planning on an engine freshen up for my sons 71 302. Since it will be his daily driver, I wanted to swap to a set of heads that have hardened exhaust valve seats. I was planning to go pull a set of heads at the local parts yard off a late model 5.0. Would there be any benefit / improvement to using a set off of 5.8? I know there is a large selection of aftermarket heads that flow great....but I'm trying to keep the $$ low for him.

Thanks for any advise

Matt

 

[Mikes73]

Look for cylinder heads off of a 5.0 powered explorer. The GT40 and GT40P heads are pretty good for stock heads with decent flow that can be picked up cheap. I had a set of GT40P's that I installed on my old mustang and that car would pull hard all the way through the rpm range. Headers are required for these heads because of sparkplug angle {sticks out of head straighter due to sparkplug location in head}. BBK unequal shorty and longtubes work well with these. On the regular GT40 heads you can pretty much run whatever exhaust manifold or header you want and these are identified by 3 vertical bars cast into the ends of the heads, P heads have 4 bars.

Good luck

 

[MotoArts]

No advantage to the 5.8 heads.

Good advise given on the GT40 Explorer heads. Personally I'd stay away from the P heads due to the header/port dilemma. Seems minor, but I think it would be a bigger pain than it's worth.

Too bad you're not closer to Pittsburgh. I have a set of late '70's 351W heads (same as 302 then) from out of a van that you could have for free. No valvetrain (I always pitched that stuff due to wear). I can't remember when the chamber sizes changed... these smog heads may have larger chambers than your original '71's.

Another head to look for would be an earlier version than your '71, such as the standard 289's had. They have slightly smaller combustion chambers that would bump compression a wee bit. Ports and bolt patterns are all the same, the 289 heads would require different rockers (cast rail type as opposed to stamped steel).

Food for thought (or am I adding to confusion? ).

 

[wwhite72]

Why dont you just have hardened seats installed and set up the heads you already own? That would be the lowest $$ build and you would see a clear improvement in performance.

 

[MattSinger]

Why dont you just have hardened seats installed and set up the heads you already own? That would be the lowest $$ build and you would see a clear improvement in performance.

sorry if I'm missing something....but how would I see a performance improvement with the same head?

Im new to Fords...and everyone seems to be telling me that the stock heads flow real bad. We arent looking to make a race car, but if we can swap to a set of heads that flow a bit better, which everyone seems to say the gt40 and p heads do.....I figured why not.

The car already has a set of long tube headers on it. From what I have read, it sounds like that should address the p spark plug issue....but I really dont know.

Im planning on going to the parts yard this weekend and looking around.

 

[mustang7173]

MattSinger,

How many miles are on your 302 engine? Installing fresh cylinder heads may or may not cause the piston rings to fail due to higher compression for the new refreshed cylinder heads. Also, the cylinder head bolts are different. Forum members, help me out here! I believe to install the late model 5.0 L cylinder heads to a early model 302, say 1971 vintage, might or will require special head bolts and shims due to the larger size cylinder head bolts. There are many kits available to do this!

Take a look at these cylinder heads-Very reasonably priced for any budget!

https://www.flootek.com/product-category/ford/

mustang7173

 

[Mikes73]

The GT40 and GT40P heads will bolt right on to a 302 engine with no special bolts or shims required, I would use ARP head bolts though. Now if you were trying to use 351w heads on a 302 you would need the stepped down bolts to bolt them on. The bolt holes are 1/2 " for 351w and 7/16" for 302.

 

[Mesozoic]

I sold a set of fully assembled (used) Edelbrock 6037s for $600 recently. I think they'd easily outperform pretty much any iron head on the market.

 

[MattSinger]

MattSinger,

How many miles are on your 302 engine? Installing fresh cylinder heads may or may not cause the piston rings to fail due to higher compression for the new refreshed cylinder heads. Also, the cylinder head bolts are different. Forum members, help me out here! I believe to install the late model 5.0 L cylinder heads to a early model 302, say 1971 vintage, might or will require special head bolts and shims due to the larger size cylinder head bolts. There are many kits available to do this!

Take a look at these cylinder heads-Very reasonably priced for any budget!

https://www.flootek.com/product-category/ford/

mustang7173

The engine has a bit over 58000 on it. Runs OK for what it is. Compression test showed a low of 125 and a high of 140. I cant remember the specific cyls right now...but that was the spread.

 

[mustang7173]

MattSinger,

Here is some more info on the E7TE vs. GT40P. Interesting.

http://webpages.charter.net/darrell1/mustang_gt40p.html

Mikes73- Thank You for responding with right information on the cylinder head bolts-

Looks like the Flootek cylinder heads take the best of the GT40P and GT40 - Explorer heads-

Please let us know what you do.

mustang7173

 

[MattSinger]

thanks for the link... good info

 

[mdan575]

I sold a set of fully assembled (used) Edelbrock 6037s for $600 recently. I think they'd easily outperform pretty much any iron head on the market.

I got my Edelbrock Heads used for $685 loaded with ford racing roller rockers. Hard to justify cast iron heads these days. After machining and rebuild you might be in for a little less than a set of used aluminum heads. Most modern aluminum heads will run circles around the swap on OEM options and save weight.

 

[Mesozoic]

Don't screw yourself with a set of cheap Chinese heads. If you're on a budget, go for used heads or look at the Racing Head Service offerings. They're made in New Zealand, flow very well, have excellent machine work from the factory, and are very good value. RHS is now owned by Comp Cams.

 

[Mikes73]

I like how the thread went from junkyard iron to aluminum heads pretty quick, while we're at it let me be the first to recommend a camshaft upgrade to go with your new cylinder heads be it iron or aluminum

 

[Mesozoic]

I like how the thread went from junkyard iron to aluminum heads pretty quick, while we're at it let me be the first to recommend a camshaft upgrade to go with your new cylinder heads be it iron or aluminum

Hahaha, yes it digressed quickly.

The Explorer heads are a good suggestion, but it would be wise to pay a visit to the docs (machine shop) before installing them if procured from a yard or used. Some aftermarket aluminum heads can be had for pretty cheap too.

 

[wwhite72]

You said low bucks? Most used heads will require some work or parts. If you take your original heads and have them decked, new seats, valves, guides, locks, springs, rockers(even oem stamped) you will have raised compression which raises HP. And with the money you save you buy a new cam (which would have to be re-degreed anyway when you deck the head. ) So you end up with a modern valve train, with an intake that already fits, and the numbers match and more performance for less bucks. If you found the right shop you could have the heads massaged and flow tested but you said this is a kids DD so not necessary. If you really wanted to bump i up you could build a Cleavor with Cleavland heads. Ha ha forget it. Too expensive.

 

[Mesozoic]

I sold a fully rebuilt 302 roller shortblock for $200 a few years ago.

Let's be candid. What IS the budget?

 

[MotoArts]

Let's be candid. What IS the budget?

^^^ Yeah, that!

Us keyboard cowboys love to spend other peeps $$

 

[MattSinger]

well....I suppose there really isnt a budget...but like I said, since its his daily driver....and hes not a race nut, I just want to freshen up the engine... and yes, figuring on a mild cam and a performer intake. If he was the slightest bit interested in more performance....Id be all over the Cleveland head thing. That said, most of these Ford parts are pretty reasonably priced compared to the Mopar parts. Last year, my oldest son and I redid a 72 Charger / 383 for his ride. This one just needs to be a decent sounding / looking ride that runs solid.