asking for advice on installing 426 hemi into 1973 340 'Cuda 4 speed

[davy442]

Hello. I'm looking to install a new 426 hemi into my 1973 'Cuda 340 4 speed.  It's going to be street/strip type build, more street. I plan on aluminum heads.  I'm going to keep the 4 speed. I know original hemi's had different motor mounts, but I think some of the new hemi blocks have B/RB mount dimensions?  I see Mancini has motor mount adapters to install original style hemi blocks into V8 K-frames?  Am I better to get a new block with the B/RB mounting dimensions, or an original style block, and use Mancini adapters?  Does it make a difference with installation of headers?  Any advice on which headers?  Do you think I need to change out the torsion bars?  Any other advice/pointers to keep my frustration level in check?  thanks.  dave.

[Chryco Psycho]

The original system , hemi Block & K frame works best .
I have installed Hemis using conversion mounts but it is more difficult with headers or manifolds fitment & dipstick tube issues .

[davy442]

thank you.

[anlauto]

Larger torsion bars for sure 

[davy442]

thank you!

[Katfish]

You'd be miles ahead to put a 3G Hemi in it.
Disregard my diversion if your mind is made up.

[anlauto]

You'd be miles ahead to put a 3G Hemi in it.

My thoughts EXACTLY

[RUNCHARGER]

Even this looks and sounds better than a G3 "hemi". And it's a 73.
I have a pattern and I build "Mickey Mouse" mounts when I swap them. I end up with a steel mount from the engine to A-engine K-member on the left side and a steel mount that mounts to the engine and uses a 440 isolator for the right side. It works very well but I build them myself. You can check with A&A Transmission as he used to furnish them. It places the engine in the exact correct spot so the fan fits the fan shroud correctly and the driveline angles are factory.
If you have a 73 brake booster you will have to cut a notch out of the back of the left valvecover so it will clear, if you have Manual brakes no problem.
I generally use the pulleys/alternator bracket/P.S. pump from a 383 or 440.
Do not buy Hooker headers, Hookers jig has been worn out for decades and the ports on their headers will leak unless you spend a few hours with a welder and flat file repairing them. Just buy TTI and bolt them in.

[davy442]

Thank you all, for all the replies!  Need to check some things out!!

The 3G hemi's are great, and maybe some day I'll do that swap?  But, I'm building this car "old school", to complement another car.  I don't want A/C, resto-mod stuff at this time.  Kind of like the car as if was built in the mid '70's or something. 

[RUNCHARGER]

You're speaking my language! It's different for everyone of course but for me the appeal of these old cars includes everything from the sound of the original starter motor to priming the engine to start by giving the carb a quick pump. If I want a new Challenger with an injected engine a 6 speed and huge ugly seats and a digital dash I'll go buy one that has a warranty.

[6PKRTSE]

Stay 2ND Gen Hemi. No way does a 3RD Gen Hemi compare in the coolness factor and I even own a newer Challenger. Tired of seeing newer Hemi's in classic musclecars. No 3rd Gen looks this cool.

[Katfish]

I guess it depends on whether you want to look at it, or drive it.
No doubt Gen 2 is cool visually, but you can't honestly say its something to drive on a regular basis.

[6PKRTSE]

I drive mine all over on the streetas well as race it. Back and forth to work. To cruise nights, car shows etc.

[davy442]

Again, thanks for comments, advice!

This car is not going to be regular cruiser/driver, so it doesn't have to be that streetable.  No a/c, or other modern amenities.  I have a viper that is my go-to driver in the summer.  Although, I'd love to have a new "shaker" challenger !!!  I just don't need another car.  Or, maybe I do ?!?!

[ignition1]

I'm guessing the 70-74 basic K-member are the same for these years with different mounts welded on for the different engine sizes. I have a '71 which I made factory style 426 Hemi steel brackets then I welded them on to my k-frame after cutting off the old brackets.  I wanted the factory appearance & use OEM mounts, I didn't care about originality and had a real '70 k-member to use as reference.

I compared the engine placement with the real hemi k-member and my mounts were maybe 1/8 off at most, but with rubber mounts I felt it was good enough.