What's it Worth? Have H.O. Is GT Better or Worth it?


Active Member
Jun 24, 2021
So this is posted ...somewhere "GT style explorer intakes $100 upper and lower GT40p heads complete, need refreshed $100/set"
I have a 89 HO. I know the HO manifolds and heads are better than the 302 and the Explorer parts work great on a 302. But how much better are they than HO parts? Is it worth it are these parts a good deal?
  • Sponsors (?)

Explorer intake is a must as thats the biggest restriction to air flow. GT40 heads are not worth the effort and cost for only 30 HP IMHO
  • Like
Reactions: 1 user
The Explorer intakes are well worth it. The heads, being P heads makes exhaust manifold selection interesting. I would get the heads, inspect them for any obvious issues, put some better valve springs, clean them up and use them. You should gain 40-50hp with $400 invested over your stock stuff with both.
Explorer intake is a must as thats the biggest restriction to air flow. GT40 heads are not worth the effort and cost for only 30 HP IMHO
You keep throwing a blanket over the GT40/GT40P swap. That is a basic low buck upgrade. I know it is not a phenomenal hp gain, but it worked on the Cobra mustang and helped the explorer gain low end torque to get that mass moving.
That said you can spend the 800-1000 bucks and grab a set of aluminium heads but if you're running stock cam, the gain will be not much more than with iron heads with comparable valve size.
And this is where a plan is needed, basically 'what I am going to do with the car'.
Basic driver: low buck 'I want to pass and keep up with traffic ' not looking to race Honda Accords'.
You need 350hp now to race the majority of factory junk being made now. Once you get to that point you should be sinking some dough into brake upgrades ($$$).
After this point (more than 350hp and other factors start to pile on including driveability, and you are leaning toward a race car.
Of course there are a slew of variables. But to say the GT 40 heads are not worth the effort is BS.
I suggest looking for the SBF head comparison on the Engine Masters show, good info there.
As always you have to watch the money, spending more than a few hundred dollars on iron heads ok, more than that you have to look at options.
If you don't have a plan, backed by research, you likely will be wasting time and money.
Of course this is MY opinion, I can understand the limitations of iron heads and the advantages of aluminium heads and I understand why you have your opinion.
  • Like
Reactions: 1 user
Swapping out the heads is a lot of work/big job for the average backyard wrench. Why do all that work for a small gain, when spending a few more bucks on heads will yield a much larger gain? My blueprint heads and E274 cam (stock duration w more lift) really, really woke up my Mustang.
Well is what I see is the comparisons of these installs to a base 302, and there is a definite performance advantage to it, but I don't see where somebody compares to the HO intakes or heads specifically, or maybe I'm just using the wrong keywords. So is what I'm thinking is if you have a ol' 302, it's a swap worth your time. If you have a HO, maybe your better off applying that money to heads of aluminum. That's more to the point I guess.
A pedestrian 302 ci engine is low compression and about 150hp/270lb-ft where the 302 (5.0 L) HO is higher compression with 225hp/300lb-ft
The heads are basically the same as are the intakes for the cars, trucks are a little different I think.