Heavy car, what to swap in?
 

The car is a 1976 Ford Gran Torino sedan. It is currently powered by a 351M (5.8L) V8 engine, 2-barrel non-feedback carb, FMX transmission (3-speed, non lockup), and drives a 2.75:1 rear gear on 215/70R14 tires.

My current plan is to find a late 80s-early 90s Ford product with an EFI 302 V8, AOD transmission, see how that runs. Then maybe bump the axle ratio to 3.00 or 3.25 to help with the overdrive (since the AOD is 0.67 it is quite deep to run with a 2.75 gear)

But I'm also thinking about a few other options. If Uncle Sam mandates 15% to 20% Ethanol in fuel, I'm going to want a 1996 or newer engine to cover that. I could use a 96-01 Explorer 302/4R70W combo, since that was the last vehicle the 302 went into.

If I'm switching to a 4R70W, why not use the Romeo 4.6L V8 from the Crown Vic? I could even leave the rear gear as is at 2.75 since stock Crown Vics came with 2.73!

On that same line of thinking, why not use the 4.0L Cologne V6? I could use the pushrod version (if it's not knocking) or the SOHC version (if the timing chain isn't making godawful noises.

Essex V6's are available in 3.8L and 4.2L sizes and will bolt up to AODs or 4R70W's depending on year.

Vulcan V6's are 3.0L but would require using an A4LD or 4R44W transmission (and those sound VERY weak for a 4000lb car but when you think about it a 3400lb short wheelbase Aerostar isn't far off).

The stock engine, when new, put out the following numbers:

351M 2V engine...152hp @ 3800rpm...274tq @ 1600rpm

The replacements, when new, could do this: (used 1999 data when possible)

'00 3.8L Essex (Mustang)...193hp @ 5500rpm...225tq @ 2800rpm
'99 5.0L EFI (Explorer)...215hp @ 4200rpm...288tq @ 3300rpm
'99 4.6L Romeo (CV/GM)...215hp @ 4500rpm...285tq @ 3000rpm
'99 4.0L OHV (Explorer)...160hp @ 4200rpm...225tq @ 2750rpm
'99 4.0L SOHC (Explorer)...205hp @ 5000rpm...250tq @ 3000rpm
'99 3.8L Essex (Mustang)...150hp @ 4000rpm...215tq @ 2500rpm
'99 3.0L Vulcan (Ranger)...152hp @ 4750rpm...192tq @ 3750rpm
'96 3.8L Essex (T-Bird)...140hp @ 3800rpm...215tq @ 2400rpm
'91 5.0L EFI (T-Bird)...200hp @ 4000rpm...275tq @ 3000rpm

I looked at the 43hp difference between the '99 and '00 Mustang engines and thought it was great until I looked at the rpm required to make it.

The 302 EFI engines are closest in performance and this car with the worn-out-pushrod-probably-all-bent-lifters-ticking-accelerator-sticking 351M still has no trouble getting up to speed and it keeps going. I refused to take it over 75 before and I had plenty of pedal left and it was breathing easy. So I would think a lesser powered engine would spend more of it's acceleration time in a more efficient mode as opposed to lugging around. But I don't want to wind it out. The SOHC V6 and 00+ Essex are out, and I want to scratch the Vulcan...but...

...I've never owned a bad one. All the Aerostars I had, the Taurus, Rangers I've borrowed, all those 3.0L's ran perfect. The rest of the vehicle might have been garbage but those motors are terrific. I'm really tempted to put a 3.0L Vulcan in this Torino. Sure it makes 25% less torque at double the rpm. Sure the horsepower rating takes an extra thousand rpm to pull. But how often do I summon all 152 horses? Virtually never!

What do you all think? This car's shipping weight with the heavy 351M and FMX is 3980lbs. The A4LD weighs 48 pounds less than the FMX. The Vulcan V6 has to weigh significantly less than an M-block (575). I'm still trying to find a weight for the 3.0L engine. If it is similar to the Duratec 3.0L, it's 325-360lbs depending on accessories mounted. That saves me roughly 250 pounds and gets me close to 3700 for the whole car with that engine combo. A few choice parts here and there...

...wonder if an aluminum CVPI driveshaft would work?

...think a 7.5" Ranger axle would hold up vs the stock 9" monster?

...leave out the AC components because I can't afford to fix it anyway?

...USB power port off the cig lighter for a 3rd Gen iPod Nano in place of the heavy stock radio/bracket/wiring harness, and wire up an RCA jack for the in-dash speaker (would leave room for a mini tach and a vacuum gauge in the remaining radio hole)

No reason this vehicle can't weigh 3400lbs like an Aerostar with some careful planning. And I'll never be carrying 7 passengers. And it's not near as tall although the frontal area is about the same.

Any other ideas? No weird aero mods or anything, I won't even put wheel skirts on it like the Broughams. But anything mechanical/swap related I'm willing to think about. Wish a 4BT Cummins diesel could fit under the hood but it's too tall (I already measured it)

I would put a Crown Vic/Grand Marquis powertrain in it. A 10 year old parts car that runs well in driveable condition should be relatively cheap. Then again, have you considered just buying another vehicle? As a person who drives old vehicles, I know that they're not expensive to insure and register, and property taxes are cheap (If the vehicle isn't already exempt). I have my old cars, and have fun driving them, but I do have a newer daily driver that I put the bulk of my mileage on.

-Jay

If your really thinking of swapping in another drivetrain i also recommend one from the CV/GM you should have more than enough room under the hood , just keep in mind that the 4.6 SOHC is physically wider longer and taller than a 460CI big block.

Don't use an Essex, the head gaskets are terrible, and the bearings crap out real soon after the first time you get a speck of coolant in the oil.

I'd vote EFI 302. But that's only because I can get a complete engine and transmission for under $100 at my local pick and save. They have at least 15 of them there that haven't been touched. Last time I was there I saw a nice LTD that had the rear end smashed all to hell with a really nice looking 302 just waiting to be yanked.

If you put in a FI engine, what would you use as a computer to run it?

-BC

Pull the ECU and wiring harness when you yank the engine.

Too bad, because if he does that, then he's boxed in on certain parameters - i.e. automatic vs. manual transmission, weight of the vehicle, rearend, etc... These are all programmed into the ECM. Or, at a minimum, he'll have to have someone reprogram the ECM (which can't always be done, depending on the ECM). Most OBD I computers are non-flashable.

I was going to suggest gearing the vehicle VERY tall - i.e. keep the 2.75 rearend and put in an overdrive with a lockup converter (provided his selected engine had sufficient low end torque). But if he is stuck having to match the rearend ratio that the original vehicle came with, that isn't an option for him. Of course if he doesn't doesn't do a lot of highway driving, exceedingly tall gears might not benefit him.

-BC

Depends on the vehicle. Pretty much all OBD1 vehicles ran a cable for the speedometer so all he needs is the gear appropriate for that differential. If he still has the factory transmission it is likely that the same speedo gear from before will go into the new transmission.

Also, depending on the year, he might be able to swap transmissions with no problems because back when transmissions were all hydraulic the ECU had nothing to do with it. Again, this depends on the year of the donor car.

Might check on the flashable or not. 80's and early 90's GM TBI ecus were flashable if you pulled the rom and stuck it into a programmer. Not exactly as easy as plugging into the OBD2 port but easy enough.

BMW 2.4L I-6 Turbo-Diesel from a mid-80's Mark VII Lincoln or BMW 524TD.

PS If you find a Mark VII get the ZF 4-Spd Auto as well.