Hello All. I Need Some Advice On Heads. I Have A 1990 302 In A F150 That I Am Rebuilding. What I Need To Know Is How Good Are The Heads On This Motor. I Also Have A Set Of Heads Off A 1993 Mustang Gt.

Upon Reinstalling The Engine I Will Be Converting Over To A Carb System And Not The Efi. I Will Also Be Installing A High Performance Cam Kit. Trans Will Be An Aod With An Approximat 2500 Stall And Shift Kit. I Have Been Looking On E-bay At The Hei Distributer. Doe Anyone On Here Have Any Prior Experience With These?

 

Stock heads are just that...stock. They don't flow very well from a performance aspect. If you want more power, it's easy to pick up a bunch with new heads.

What are your objectives for the motor? Lots of power? stock rebuild?

 

I Just Want A Daily Driver With A Little More Hp Than Stock.

 

Well, depending on your budget, you may want to look at a set of GT-40Y heads. They are about $700 brand new which is a great deal for the dollar. They are a mid level performance head, which will probably get you another 40-50hp over stock. They come with new valves and springs all setup to install. Top it off with a set of 1.6 roller rockers and you'll have a nice running motor for under $1500. The roller rockers are probably $200-$250, they will lighten up the valvetrain and reduce friction. They help the motor spin smoother I guess you could say, and make an extra 10-15 hp. That would be about $900, you may need some computer tuning maybe not...but the $1500 figure includes $600 for extra miscellanous stuff you might need to finish the build.

AFR makes great heads (arguably the best) for that motor, but at $1400 you'll be payin for em'. CarCraft took a stock 90 or so mustang 5.0 and put AFR 165cc heads with 1.7 roller rockers (stock cam, stock internals, everything else stock) on it and after the dyno run they saw a smidge over 400 hp. There is a lot of hp to be made in heads (the 165s are AFR's smallest, they go up to 225 or higher I believe) but I think the GT-40Y heads are a good compromise. They are right in the middle of a stock head and an AFR head. With even a stock bottom end, you could put the GT-40Y heads and 1.6 or even 1.7 rockers on it, stock mustang camshaft (actually good for a truck believe it or not), and see 300hp or so. That's a nice number for a daily driver with some kick. My buddy has a 94 mustang cobra with about 300hp and it's great, top that engine off iwth an edelbrock truck intake or ported stock intake and it'll run like the wind. Could even see 6200 rpm on that motor. Put some ARP rod bolts in the connecting rods, and you'll be able to see 6500 rpm...

 

Thanks For The Info. But I Am Trying To Work With What I Have. If I Were To Have Some Porting Done To The Heads Which Would Be The Better To Work With The 93 Gt Heads Or The 90 Truck Heads?
(not Sure What Casting..)

 

They're probably the same E7 heads...

It'll cost ya $500 or so to port them, and only a professional can get really good flow out of them...for a little more you get a direct bolt on head (just like the stocker), GT-40Y's are Ford's aftermarket heads. You can have them shipped to your door, a lot easier than dealing with getting the other heads ported.

I had to select what heads I wanted on my 393 ci stroker (from a 351). The 302 and 351 use the same heads, I got the GT-40Y heads for my stroker engine, it'll make around 400hp with the other parts that I have. I didn't bother with porting my stock heads, it costs almost as much as the GT-40Ys and get you similar if not lower performance numbers. The GT-40Y's can give you good flow for a little extra, and later on in life if you so choose you can port them to get even more vs buying another head...

Also, the GT-40's are aluminum rather than cast iron. That takes a good 50 lbs off your motor, and it looks better.

I don't mean to try and sell ya on it so much, but I guess what I'm doing is trying to help you understand not to limit your options. I have recently built an engine with advice from people here and in books. At first I wanted a $3200 302 engine....I ended up wiht a fully custom 393ci stroker with 400hp with a price tag of about $7000-$8000. Not that you would do that, but I'm just suggesting to always evaluate options to the fullest when building an engine...it's the only way you'll end up satisfied in the end.

 

It would be allot cheaper to pick up a set of GT40/GT40P irons.Reputable e7 porters like Thumper of Orange park charge 500-800 dollars plus shipping to port e7s.You can find unported GT40s for 200-350 easily the Thumper e7 heads are a bit better,but the GT40s have bang for the buck and room to grow if you decide you need more power down the road.That said i'd save some money and get a set of Trickflows or AFRs nothing beats bolting on 75-100 hp.

 

The GT-40 irons and the GT-40P's IMO are questionable.

Think of it this way...the GT-40Ps require a special header, it will be tricky getting the exhaust system taken care of, I don't know how available those special headers are for the trucks. I know they make them for mustangs, but trucks...I duno. They came on the 97-98ish Explorer 5.0Ls and they still don't have that great of airflow...

The regular GT-40 heads are not all that much of an upgrade either. Are you saying they are 200-350 each or together? Used or new? I'm not sure of their value, but the $700 is for both of the GT-40Y heads.

 

You can make a difference on those E7's by porting them yourself. By the way the Stang heads are the same castings. What you can do to them is open up the exhaust side by removing the thermactor bump in the port roof. Then you can raise the roof to match your gaskets and also open the port sides. Then blend this down all the way into the bowl under the valve. Leave the floor as is, and polish the passges when done. On the intake side, just remove any sharp edges, port match the openings & blend the bowls. I did this with a set of E7's and while not being able to dyno the results, just knowing the exhaust's flow more than before after my work, I'm sure the result was worth the effort.

 

Mac sells shorties that fit and most longtubes will fit the P heads.200-350 for a set and there easy to find.The GT40Ys are worth around 15-20hp over the iron GT40s,but they'll also cost twice as much(Maybe more) unless you find a set used.Thats not likely though since they never came on a production vehicle.The Ps came on Exploer's and the normal GT40s came on Cobra's,Explorers,and Lightnings.

I believe the 90 truck heads and the 93 Mustang heads are both E7s so it doesn't really matter which ones you port.

 

Well, you're saying they are 200-350....but I am assuming that is for a used set. If I were to pick those up, I would have them all re-built before putting them on my engine...and that costs a few hundred more as well. It's a touch decision I'll give ya that

 

The GT40 iron heads were also used on 89-up Marine engines too.

 

It's not at all difficult to come up with headers to fit the GT-40p heads. Many header companies have been building headers with oval ports for years. When I got my P heads I dug through my stock and found two sets, plus a DIY header kit that I never built with oval ports on the flanges. The bigger issue is the relocated spark plug position that can cause a pretty tight clearance problem, usually on the driver's side header. My pass. side header was a perfect fit as is, the driver's side I totally rebuilt but it's going in my Ranger and I wanted it to clear the steering box by a healthy margin, as well as have good frame and steering clearance. I did a mild port clean-up and valve job on these heads as well as milled the stud bosses for screw-in studs. I did everything myself and used parts that I already had, so my expenditures on these heads were pretty much limited to the purchase price. (Besides, I'm really cheap so I like to save a buck anywhere I can!)
I came across this page about porting E7s, so you might take a look. If you already have them, that's probably what I'd run. I'd already bought my P heads and then I was given a pair of E7s, maybe I'll rebuild 'em and port 'em and put 'em up for sale...who knows? Anyway, here's the link:

http://www.mustangcentral.net/tech/e7.html

-TD

 

where can i get those GT-40y heads?

 

they're all over ebay