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What all is needed for gt40p swap in 5.0

2905 Views 6 Replies 4 Participants Last post by  SigEpBlue
I understand there are header issues that have been resolved, but being they are "roller cam" heads is a roller cam needed? Found a thread that mentions different pushrods needed? I havent found a thread that details everything involved in a gt40p swap (may have missed it). I will be installing these on a 1990 5.0 in a Bronco with a bent/burnt valve (no compression, not throwing oil). Seams more cost effective to swap to gt40p heads as they are as much or less for a set than getting stock heads rebuilt, if not to much involved. I was planning on getting headers anyway. Thanks for any help with this! :popc1:
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Sorry, guess it was in wrong board. Gotta do something this weekend in the way of heads, either get stock fixed or get a set of gt40p.
All you'll need are the special headers. Everything else is pretty much factory 5.0L equipment. Unfortunately your air injection reactor (AIR), or Thermactor, pipe that goes into the back of the heads will have nowhere to go. The GT40P heads aren't equipped with the passages and ports for exhaust port injection, so if you're in an area with smog testing, you may have to rebuild what you have.

Click here for a lot more information.
Thanks for reply Blue, no smog test here yet. Sounds like i'm in buisness.
GT40P heads should be a bolt on for your 302. Pushrods and all should work fine. The valve springs are designed for the more aggressive ramps of a roller cam, but should work fine with a mild slider cam.

For a performance gain, try grinding the thermactor bump out of the exhaust port.

The header problem stems from the spark plug angle. It was revised for use in the exploders. Stock manifolds should not present a problem, to be sure you should trial fit your headers / manifolds before you install the heads.

Disregard the red words, I have since figured out that these holes are the exhaust ports for the EGR. They need to be plugged on a boat.

This is the back of the heads on a fuel injected 351W in a ski boat. Its the 310HP marine engine with the GT40 intakes. I'm not sure if they are GT40 heads you guys are referring to, but I cant imagine that changing the 2 intakes to the GT40 would give a 100 HP increase over I'm assuming the heads are the GT40 as well.
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There are no thermactor bumps in GT40P heads.

There are no AIR injection ports in the end(s) of GT40P heads.

Bolt on, have fun. :thumbup
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