Engine Ford Explorer GT40 intake and heads
- Thread starter RJ'SDAD
- Start date
Many have. I actually purchased a used motor a year ago that was that exact combination (actually it was an E303 with 1.7 roller rockers as well). I changed the cam for something else but it should be no issue. As always with any cam change, piston to valve clearance should be checked.
The gt40 iron head springs will most likely put up with a stock cam.
With that said, gt40 iron stuff is barely worth the effort with a cam, without it the value drops even further.
Me personally, i'm not taking the heads off my car to rake in 250rwhp total.
With that said, gt40 iron stuff is barely worth the effort with a cam, without it the value drops even further.
Me personally, i'm not taking the heads off my car to rake in 250rwhp total.
Why is that? I'm looking at doing this swap eventually, so good to know what all needs to be done.
The explorer cam is a mild truck cam.
You go too far from that and you will have valve float.
Basically the springs can't keep up with the cam and could leave a valve very briefly in the wrong position.
With the stock mustang cam i'd guess it could be ok, but at the same time as i said above, why go through the trouble of swapping heads and leaving the stock cam.
With an aftermarket cam, floating the valves eventually is almost certain.
You go too far from that and you will have valve float.
Basically the springs can't keep up with the cam and could leave a valve very briefly in the wrong position.
With the stock mustang cam i'd guess it could be ok, but at the same time as i said above, why go through the trouble of swapping heads and leaving the stock cam.
With an aftermarket cam, floating the valves eventually is almost certain.
Your best bet with these heads is to get the right set of springs (the info is around here somewhere) and take them to the machine shop for a valve job. They will install the springs, shim as necessary and get the seat pressure right.
A good valve job in worth quite a bit of power for the $200 it costs.
You could do the springs yourself, but the reality is that you will be putting heads on your car that had over 100,000 miles on them. No explorer was low mileage.
A good valve job in worth quite a bit of power for the $200 it costs.
You could do the springs yourself, but the reality is that you will be putting heads on your car that had over 100,000 miles on them. No explorer was low mileage.
The GT40p factory valve springs can't take anything over .450 lift. Visit https://www.alexsparts.com/categories/FORD,-SMALL-BLOCK-302-HO-&-GT40P,-GT40/ for an affordable valve spring kit for these heads.
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