Building/Buying a 400+ HP 5.0 to drop in Explorer

[King$nake]

Hello,

I am at the point now where my truck has 150,000 miles and it's just so underpowered for towing, especially since I lifted it and am running 33"s. The 5.0L is still running solid, but I want to start building off a long block in the garage, take my time, do it right - and then when it is ready, swap it out with my current 5.0L.

So, with that said, I was thinking of starting with a 302, 306, 347 or even a 351W long block to start off with, buy some heads, upper/lower intake, etc, etc. I've built some modular motors in the past but definitely going with pushrod for this setup.

So, a few questions - if my goal is 400+ Crank HP, what would be the most cost efficient way of getting there? Power is one thing, but the main idea of this is to 'renew' my vehicle life so I think I want to go with new parts across the board.

Also, my current stock auto trans has been rebuilt, but I am thinking I may need to go with a C6 or something of that sort. Thoughts on the trans?

Thanks in advance. Already have an engine stands and the necessary tools, ready to get started after I do some more research

Here is a pic of my truck as it sits:

 

[Turdle]

For several reasons a 351 will not work without investing a lot of $$$ just to fit it in the plan.


Keep the 4r70w and go for the 347 cubic inches.

 

[King$nake]

Ok, so I would assume since I am going with an all new engine I can just build a 347 designed for a mustang? Meaning I can have mustang balancing, etc and it shouldnt be a problem? I would assume the balancing, etc would only be an issue if you are interchanging parts.

I have a feeling there is a writeup on here about a 347 swap so I will look into it

 

[Turdle]

That is where it gets tricky, you'll need a custom balancer.

 

[bigtang]

i'd be less interested in 400hp and more w/ the torque. I can put a 400 RWHP 302 together but you aren't going to like it in an explorer, it didn't make peak power until 6600, make less than 200 rwhp all the way to 3500, peaky isn't even the word for that dyno chart)

Go 347, change the front accessory brackets to work if you have balancer sourcing issues and limit it to 5500 and expect 350 hp and about the same torque, any more and you'll be doubling your cost and getting minimal gains in return.

that said, 347, TFS TW heads, custom cam(ed curtis) TMOSS ported stock intake OR RPM2, no reason to expect big gains. no reason to try and pump more air in since there aren't a lot of choices on getting the air out of the motor besides the shorties that are available.

I'd stick a build 4r70 in there and be done w/ it but if you must swap avoid the C6, a build c4 is cheap and will lower your MPG just as effectively as a c6 ever could.

 

[FatJoe]

ok im not really a explorer guy just looking to get one very soon but i am a mustang guy...and if you want power and longevity i would think the 351 would get that hp eaiser then a 347 and the 351 would last longer.....is the 4r70 the same trans thats in the new edge mustangs 4r70w???

 

[Turdle]

2ticks to the 351 would be the oil pan clearance and a cam sensor being fitted.

 

[LordBear]

just build a strong 302 then slap an sc on it..lol

 

[94Eddie]

IMO, you shouldn't be thinking in terms of horsepower and instead thinking in terms of torque. If towing is a concern then make your build for low to mid RPM torque. This requires a different strategy than building for high RPM horsepower. This requires that you choose the intake and heads carefully. I would recommend calling Trick Flow, Edelbrock etc. and discussing what combination of their heads and intake will give the best low/mid RPM torque. The cam you choose will also be very important. High flowing heads, intakes, cams, throttle bodies etc. will kill low/mid RPM torque. I recommend staying away from them. I would do a 327 CI (no boring the cylinders unless necessary) at most. This with the right heads/intake/cam/throttle body will give you the torque needed to make for a good towing rig with decent horsepower as a side benefit.