I have been narrowing down my hoard and have gotten down to one ride. I kept the best of everything to build a 6-700 hp big block '74 Challenger. I even got the Gear Vendor OD, dana, etc.

It has been a couple of years since the car has been together for one reason or another (paint prison, broken elbo, health, etc.).

It finally hit me a few months ago when I was in Nevada, that driving a car like this cross country is going to cost me in more ways than I could shake a stick at...

I might be lucky to get a 100-150 miles to the tank in the mountains. Would there be gas stations, etc, etc.

I am now going in the stock motor direction for my car; 360, A500, 3.23 8 3/4, etc.

If you were building the motor for fuel mileage, torque, 87 octane, and just enough hp as to not require feeding the horses; how would you build it? I would like to stay with the LA engine even though I know that the magnum would be a plus. I found a '74 360 block for a foundation. I think a stroker might eat too much fuel. Any real world experience?

Get trailer and build a big motor.

No real world experience but I've given it some thought lately. I think if you start with a solid plan and go for efficiency in every part you put in, you can still end up with a very fun car.

Engine, definitely magnum 5.9 as a base. Roller lifters, lighter rotating assembly, improved flow in the heads. Stock exhaust manifolds for torque, air gap intake for cooler air charge, 600 AVS or 670 street avenger for vacuum secondaries. Smaller cam like the Edelbrock Performer. Could be built fairly inexpensively.

I would put the real money into a five speed like the richmond street unit. I think I calculated with 3.23 gears in the rearend it would launch like it had 4.10 and cruise in OD like it had 2.76. Not sure on the Keisler unit, which may be easier to install. Clutch means no slipping and power loss from a torque converter and no front pump to drive and loose power on.

My 400ish hp car is pretty dang fun.

I got a little "real world" experience. Here's my 340 car at 14000+' at the top of Pikes Peak.
It's tuneup is drastically different than when I'm at home at 800'

I trailer my car all over the US and drive it, I change the jetting and timing depending where I' at. Tow it behind my toterhome and use it for a driver while we are on vacations, it's a blast.

Here's my pipes after a day of 120 mph blasts out on the Bonneville salt flats at 6000' I ran over half a tank fuel out at over 100 mph on a 95 degree day with the AC running all day. The tune up has to be right for that kind conditions. Fuel injection sure would save my back when changing needles on my carb.

Then a day or so before that we are at sea level.


Salt for as far as you can see, there truly is no speed limit. There was some folks walking out on the salt watching me blast my car by them at 120 miles per hour, it's killer.

I have a good set of cnc eddy sb heads from MCH, the rpm airgap intake. I know the heads are overkill.

The A500 (lockup) and 3.23 ought to make a good package; first gear should be like a 3.7 gear or so, 3.23 gear for city driving or hill climbing in drive, and about a 2.22 in OD.

I was actually thinking a 500 AFB for snappy throttle and good brake specific fuel consumption (BSFC) from the small primaries. A Thermoquad would be ideal if I could trust the tune.

Choosing the right cam and compression ratio to get the best overall torque and not too shameful hp would be the key.

The car itself will be a restomod, lowered with good handling components, (Hotchkis, PST, RCD, Dr. Diff, etc.)

Fuel injection is a couple of grand that won't be recouped to easily. I can always bolt a larger tuned carb on it for other kinds of driving.

Challenger 1, I have seen your pics before and they are part of my inspiration to do a trip along whats left of the Route, the Flats, etc.. I do want to drive the car the whole way, not tow it.

When the car is done, I was thinking of looking for other like minded Moparts members who want to travel the Route at the same time. Perhaps try to time things with car shows, events, vender open houses, maybe some road course type of events, etc.

I'm going 440 in my Barracuda convertible, but if I were going small block it would be a 5.9/A500/3.55 (it does have 3.55s for the 440 already) with factory fuel injection and computer controls. I get 17-18mpg in my Durango (same drivetrain as indicated above except it has a 518) on the highway. In the lighter Barracuda it would likely be over 20, maybe as high as 25 and still be fast enough to be fun.

With a nice tall final gear ratio like what you're talking about, I'd be thinking stroker, unless MPG is the main consideration.
'74 Duster I built has a 406" 360, very little work to the heads, cheap headers, Engle 214/224 @ .050, .470/.504 lift cam, T-quad on Eddy intake, big oil pan. TF, 3.21 gears and a 28" tire, it pulls 17MPG @ 70, runs the AC fine, sounds very healthy, and has great throttle response. Taller gear would help the MPG. 9.0:1 is max CR with iron heads & 91.

I have real world experience. I live in Hawthorne NV 300 miles from Vegas,132 from Reno,266 miles from Saramento. Open roads
This is my combo 340 block 4.100 bore,4.00 stroke 11.2:1 compression,Harland Sharp 1.5s riding the stock Eddie valves and ports to the tune of Hughes 234/238*? 550ish lifts "older hydraulic flat tappet cam. M1 single plane intake topped by a BG 750 sportclaw very well tuned. Initial timing 18* 34* at full mechanical and vacum advanced at light load = 49* total timing. TTI headers into 3 inch doctor gas X pipe through flowmaster delta flows into 2.5 tti tail pipes.
No power steering or brakes.
Aluminum flywheel,Centerforce dualfriction corvette sized clutch and pressure plate for less rotating mass.
The trans is a TKO 600 with the .82 OD 5 speed. Rear axle is 8-3/4 SG 3.23 geared. 275/60/15 BFG dragT/As.
70 mph is at attained at 1700RPM in OD.
Mileage well that is as high as 22 mpg or as little as 12 depending on level of restraint or lack there of.
I have never gone to Las Vegas on one tank but have made it home on one and its up hill, and against the wind always or so it seems. I am always in a hurry to get there and never rushed to get home so 70 to 75 is the norm. I have gone round trip to Reno on one tank just to do it but fuel costs more here so only once. Going to Sacramento on one tank was way too easy had a 1/4 tank when ariving at the drag strip. Its a good quick grade to the top of the Seirras per say and a long easy descent into OH MY GOD MY CAR FEELS LIKE ITS ON NITROUS LAND. SAC is near sea level, home is 4500 ft elevation with air that is much worse usually. So can you have POWER and economy yes, is it work yes? Is it fun OH yeah.
So do I have the ultimate car HELL NO.
But its mine and it has a balance of what I like,its quick enough 12.4@ 116 crappy 1.98 60', fast enough to keep an 03 mustang cobra top ended and spanked to the top end. It's old it's iron and I like it.

If I'm going on a long trip and I'm worried about fuel costs, I just leave the Road Runner, Duster and Demon at home and I drive my 69 Charger... 318, 904, 2.94.

I am not after the ultimate ride. Changing drivetrains is not an issue if all the parts are available and ready to use. I am just thinking that for a long term trip that may take several months to do right, mpg and low investment are key. I might wind up liking the combination and never put the BB back into the Challenger. The BB stuff can be planted into something, somewhere down the road. I did consider detuning the BB to the 500 hp side with big torque, but I have some good sb stuff and a thousand $ or so to make work, or spend another thousand to make it stouter.

I am leaning towards the minimum amounts spent to get fun results with mpg as a priority. I was offered a 3.9 and A500, wiring/computer complete in working condition free. That just doesn't seem right!!.

Yup: Why have the car if you are going to trailer it? I built a 383 for my truck just for this reason, I could have built a 500 stroker but the decrease in fuel mileage doesn't make any sense.

Sheldon

I'd grab the 3.9/etc. for a future A-body project if it were free...

Yeah, I know what you mean about storage, but if I came across that deal I'd probably find room even though I really have no plans to build anything other than what I already have.