I’m not trying to spend your money but if it was me I would swap it. After driving it around a good bit my truck definitely pulls better from mid on up. If I had the engine out I would have replaced the heads altogether. I’m actually looking for a set of used heads at a decent price. I think you said you wouldn’t sell your heads but I would & will when I swap them to recoup a little of what I spend. If you haven’t I would replace the springs with a new cam.
I'm not sure if I was clear enough when I first posted. I have a tendency to make confusing posts when I'm feeling good, and I've been fighting the flu most of the week. Getting over it, but head still ain't right.
So I have 2 engines.
1998 Explorer 5.0L
- Knew previous owners and it was well maintained prior to rollover. Ran good after rollover, but wasn't able to drive much more than onto trailer.
- Valve springs upgraded with kit from Alex's Parts. Don't recall the kit but it was supposed to be good for stock Explorer, stock mustang, and maybe something like the smaller FR letter cams. Been too long and I nolonger have the order information.
- Replaced valve stem seals when doing springs. Really more like the opposite, doing seals so replaced the springs.
- Installed 1.7 Ratio Roller rockers to get more from stock camshaft.
- Installed appropriate length pushrods
- Installed mustang valve covers and an intake spacer to clear the rocker arms.
2000 Explorer 5.0L
- Purchased 3 weeks ago, no history available
- Had oil and coolant, first drive was the roughly 100 miles home.
- No issues other than rust falling off with every bump, but can tell it's been used hard and not as well maintained.
- All stock and similar mileage IIRC.
I'm figuring on having a few stages to this build since I don't have a good place or time to do everything I want at once.
Phase 1: Get the swap done and truck running, usable, and hopefully reliable
Phase 2: Get suspension work done. Might happen first or concurrently due to parts needed with the AWD t-case.
Phase 3(?): Build & install spare engine, stout transmission, and tuning.
Phase 4(?): Paint and Body.
I'm not discounting your do the heads while it's out idea, but I want to get it running first. The engine will be coming back out for replacement anyway.
As for the heads. Even when "built" I'd like to pop the hood and have it look like Ford did it. If Ford did it in 1999 they would have used the same GT40P headed 5.0L used in the Explorer. I know that I'd be leaving power on the table, but this ain't a race truck. It also ain't a show truck, under the hood will probably never be very clean. I'm after a quick fun truck that I've built the way I want to and I can enjoy driving. That's not to say that plans won't change and evolve into something more, but for now I don't think that is what I want.
Also if I'm picking a place to sink big money into an engine, the F-100 has got to be the target. Either the FE has to be built or it's getting a swap (7.3?). Since that will eventually be a restomod project, it's getting done right.