Well, I know this is going to get all kind of opinions but need some help. Doing a resto on my son's 72 Cuda. Was an orignal 340 /3 speed car. Motor trans long gone. Started out as a budget build cause my son is in college. well he graduates in May and has a job. YEA !! So he will have college debt etc but now he can build more on what he wants . so the question-What motor to build? Wants a nice driving car 450hp + that can be driven daily. Car came with a 72-340 cast crank needs complete rebuild, Have a running 360 magnum motor with 84K on it.( see these 360 builds putting out 450hp) Or thoughts now are to find a wrecked Challenger 6.1, 6.4 with a stick and install that set up. Trying to find expense of a swap to gen 3 and what it will take to do a gen3 with a stick. What forum would be the best to get thoughts on an over all resto input?? Thoughts on build/ motor??

Hemi. Not really but I wanted to say it first

450 horsepower isn't much of a challenge anymore with a Mopar with the distributor in the front or back. If you have a small block, build a small block. You won't need to buy all the different stuff to switch over to a big block. Using what you have is probably going to the cheapest route. But 450 out of a 440 can be done with cast heads, stock crank, stock rods, etc.
Buying a crate 6.4 will give you 485 and you don't have to build anything. Motor mounts are available, headers are available, and running a manual transmission is as easy as bolting an 833 to a small block.
But there's something to be said for the savings of using what you already have. My vote is for a small block.
The 340 with a 4" stroke crank and decent heads and compression will be an easy 450 horsepower, and mild mannered.

Hard to get any cooler than aHemi Cuda. Go for it!

450HP begs the questions "how streetable/mild-mannered" and "what's your budget"?
360 LA vs Stroker SB vs Gen3 comes down to budget, what you can find in a good/used Gen3, and what you need to buy or fab.
Fuel supply, electronic support, exhaust, converter & trans, maybe shifter are part of the equation too.
GoodysGotACuda here did a Gen3 into his SB '72Cuda as part of a complete & gorgeous rebuild of everything; a good thread, he should be able to give you good info.

If it was me I'd use the 340 block and add a stroker crank. Probably use some Edelbrock heads with a Performer RPM intake and a Super Sniper EFI system. That would be a fairly easy build that would give you good power but be very driveable.

340 stroker would be my first choice, followed by magnum engine stroker. Either one will get you the numbers you want.

Your 450 horsepower goal is so easy in today’s mopar world. If I only wanted or needed 450 horsepower I would sell the 340 for several hundreds and buy a 50.00 360 engine. My preference if money permitted would be a 4 inch stroke 408 with a set of ProMax or slightly modified Sidewinder heads. Talk to one of our cam experts or call Jim at Racer Brown cams and he can fix you up. A gasket matched victor340 and a 750-850 Holley double pumper and you are there. Compliment your build with a set of 3.55-4.10 gears and at least a 4000 stall convertor. You 450 horsepower can be made with the stock 360 crank too so pick your poison.

ok , I'll start looking into my options. Thought if we did a Gen3 and he would have a daily driver that got pretty good mileage. I'm amazed how good my SRT8 gets.It's going to be a stick car. Would like to see what mods are needed for the 6 speed.

Part the floor pan like the Red Sea, cut the torsion bar mount, clearance for room, box it back in, build a transmission hump, build a transmission crossmember, build a driveshaft,install a hydraulic clutch setup, etc etc etc. If you're paying to have all that done, you could probably build 2-3 450 horespower 408's for the same money! Lol.
Of course if you wanted me to take the ragtop off your hands to give you the extra space to fabricate the stuff, I can do that...

I built Nine second Phil a 416 C.I. pump stroker 340 block that made 512 HP with slightly ported W2 heads and Mopar cast single W2 4150 intake with a 850 BG Street Demon using CA pump Swill back in 2002 or so, he put it in a 1969 Baracuda fastback that would run low elevens on the motor only on pump swill
With the better heads and camshaft selection your goals are not hard to achieve
BTW, building either a 340 or 360 block will give you the same results

Well , getting ready to weld in torque boxes, frame ties- whats a hump and a cross member lol. Could still do a hemi and a 833 .

That would be easier, it drops right in.

My wife's Challenger has a 360 +.060". Built years ago before good pistons, aluminum heads, and stroker cranks. Stock ported head (some truck stuff, nothing fancy). 9.0-1 TRW, runs on 86 octane. 224@.050 Crane hyd roller, LD 340 int, 650 Holley, TTI headers,2 1/2 exh. With 3.55 and sticky tires 12.70's@107, slicks and gear 12.50's@110 in street trim with air cleaner and full exhaust. It's a 4 speed with only 2.42 1st gear. I'm sure and auto with a good converter would be better. The late Hemi stuff would be nice but many extra parts to get it completed and installed
Doug

Your budget isnt completely clear from this post, but I'll assume its not as simple as " money is no object".

As much as I love a BBM, for a street car, I simply like the SBM better for a daily driver for two reasons. One, thing fit easier. Two, the lighter weight of the SBM , makes the front end nose weight far less, and simply they drive and handle nicer.

I would, without question, stroke the 340, use a set of Sidewinder heads with a clean up and a proper valve job, go with one of the EFI set ups , and not look back. Straightforward, easy to build, and within a reasonable budget. Just good solid combos.

If you already have a 360 Magnum, 2 options there too. Throw a set of EQ or RHS X heads on it, and it will be a strong runner.

Gen3 certainly all the rave now, but it comes at a cost and more install work. Just depends on what your really looking for.

I had 2 customers at the shop yesterday morning with this exact situation.The 408/416 combos simply made it much more affordable for them to get their projects on the street.500HP on the street , is plenty to get into trouble. Just my 2 cents.

I like all the small block comments so far since I agree that everything fits easier, but since it's a '72 Cuda I'll throw out one more option.
A 400 block with a 440 crank which will give you 451 cubes. You can build it very mild, it will have enough torque to run a streetable tight converter and 3.23-3.55 gears, yet has the ability down the road to be slowly upgraded to a 10 second car when you get bored. My 451 with Eddy heads eventually went 9.89 in the 1/4 and it was a pump gas motor with the 590 cam at 3050 pounds.
The 408/416 small block should be plenty though for what you want to do, I just wanted to give you one more very mild streetable option that could be upgraded over the years.

IMO use what you have to build a nice SB with EFI. Why burden a new grad with more debt or take forever to get him in a cool ride. Plenty of options to build a nice SB, the car is set up for it already and you have some of the pieces. He can always upgrade the car later with ease, but why waste time right now when he could enjoying the car this summer.

Most have pushed you to a stroker LA base with aftermarket heads.
Me I would go G3 .
Stock 5.7 with a cam , long tube headers and FI will net you 450 all day long with 22 MPG .
Now the hard part. Converting will take some knowledge but it's not rocker science!
You don't need FI you could go carb but intakes are more.
Matt

I can’t unders all the love for Efi on old school builds. We have a few members that switched over, made all the tech calls, and their combos still aren’t running right. Carbs are so easy to make right at wholesale prices. I guess it lacks the “cool kid” factor. Lol

Great info going on. friends talk to me going with Fitech. But im hearing alot of different sides. Taking in all this info and putting together. Owned a few 340 motors over the years.Great motors. Was reading in a few magazines about these magnum motors. Thought they were the way to go, but hearing guys still feel the 340 is still the way to go... Ahhh, like trying to buy a pair a tennis shoes, in my day it was either Black or white Converse lol. Now days quite a few options to choose. I'll start putting a spread sheet together with all my options. Lol learning how to do spread sheets at my age lol. This is great info guys ! I like the fact of all the input from all, cause hate to do trail and error when you guys have all ready learned. Truly appreciate all these options. Can use help on this whole build,body suspension etc. Thanks. Drop me an email if you like par12730@sbcglobal.net