I think you said you have a C6 tranny now so I imagine you'll like the 4R70W a little better.  I'd be less excited about the  '98 vintage sbf when considering the amount of work for the whole swap...I'm guessing the power and mpg will be only a little better than the current I6.  A coyote 5.0 would definitely be more exciting.

No more work than anything else, really.
Yes, a Coyote would be more exciting. It would be exciting to have the money to purchase everything I would need for the Coyote swap as well.
Not going to find a Coyote engine, transmission and all the wiring and fueling to swap into my truck for a grand--which is what I am paying for the entire Explorer. Disc brake rear axle I believe there too, if I care to use it. 

Well, a little different turn of events here.
Made a deal for a 1998 2wd Explorer 5.0 and will be using the entire powertrain from it. The engine runs great and idles smooth, however it does have 170,000 miles on it.
It does move forward and back under its own power but as far as running through all the forward gears, that is undetermined at this point.
Pretty excited about this. GT40 style intake manifold, GT40P heads, coil pack ignition system and a small, pea-shooter cam. Should be a nice, torquie, smooth running package for the truck with decent MPG, I would think.

I have never owned a 351C 2V, but in the mid-late 70s, I owned 2 different M code 70 MUstangs, a Sportsroof with Shaker, and a Mach 1, with no Shaker. Even with the available 100 octane leaded Chevron Supreme back then, these engines were very sensitive to pinging/detonation. For best power , it needed more timing, but it was a juggling act to get enough total timing, without pinging on a warm day. And pulling back timing really killed the power. The Sportsroof I drag raced pretty much every weekend, and also did a LOT of street racing in between. It was all stock, except I put a pair of Cyclone headers on it in 1976, and they were both FMX cars with 3.25 gears. Not sure how the 2V heads would compare, but with the big 4V heads, both cars were soft below about 3000 RPM, then wake up, but around 55-5600 RPM, the stock cam gave up. Compared to my later 428CJs, the 351C 4V was much more sensitive to weather conditions, when the temps would change from 70F to 85-90F, it was not uncommon for the 1/4 mile ETs to fall off by 1/2 second and 3-4 MPH.

Wow, that's interesting, Rory, thanks for sharing. Never heard they were sensitive to weather changes. Also, the quench heads were supposed to be way better at detonation prevention, but evidently, not in your experience. That's disappointing to me.

My 2V engine has excellent off-idle and low RPM torque and throttle response--it feels "lively." I guess kind of opposite of the 4V engine. I tend to like low RPM torque and throttle response over high RPM power for the street. That's why I like FEs and big blocks in general.

Man, I might stick with a 2V engine then. Since it's a street car and I won't be racing it, I'd rather have the low RPM power the 2V heads provide. But if I can't overcome the pinging issue, there's always the option of throwing another style engine in it, like maybe an FE or even a 460. Being a 1970, either engine family would be correct for it. 

Thanks guys. This engine won't be in the car forever as it is an M code car which means it was originally equipped with the 300 horse 4V Cleveland.
Eventually I plan to build one for it but in the meantime while I work on the rest of the car, I would like this engine to run the best it can for as long as it can. As we all know, detonation isn't conducive to either one of those deals. 

Have an excellent running 2V Cleveland in a 1970 Cougar I recently acquired but it pings under a load pretty badly.
I have always heard these engines with the open chamber heads were detonation prone and from having owned a 1974 Montego with a bone stock 2V Cleveland that pinged under a load and now this one, I would tend to agree. When I say under a load, I'm not talking wide open, just partial throttle climbing a moderate hill.
Now, short of swapping heads in favor of the Aussie heads, 4V closed chamber or running race gas, is there any way to remedy this situation? Would polishing the chambers help?

This engine I have now has a Holley 750 vacuum secondary carb., Holley Street Master intake, long tube headers with dual exhaust out the back. The mufflers are very quiet chamber style.
It needed a fuel pump so when I removed it, I could see and feel the timing chain was worn out. So, replaced that as well, and when doing it, removed the pan to make removing the timing cover easier. While the pan was off, replaced the oil pump and pick-up with new Melling stuff, standard volume and pressure.

The bottom end looked stock. The timing set was the factory nylon deal so I believe the cam is stock. it idles very smooth.

Haven't checked the timing yet because my timing light is at work. Will do that in the next day or so. Have the distributor mounting soaking with PB blaster as it's stuck.

That car's awesome! Thanks for posting!   

My '66 F100 that I run around in gets a little over 16 mpg with a basically stock '68 390/C6. I do have an Edelbrock F427 intake on it and a 600 Holley and a Pertronix conversion but that's it. Since all I do is drive it...no towing I put a 2.50 rear gear in it out of a '77 Ranchero. That makes it run down the road real nice. at 65 it's only turning about 2000 rpm.

Nice truck, Alan.
I'd be very happy with something like that. If a person could get that kind of mileage out of a 390, seems a 352 should equal or better that figure I would think, no?
Or maybe 390 cubic inches is the "Goldilocks" size for the FE engine design that brings the best MPG per work done.
Seems like I remember being told years ago by people who owned 390 powered vehicles that they got pretty decent mileage. But maybe I'm manufacturing memories. lol.
What cylinder heads are on your truck engine?