408/46rh in Cuda finally on the road -WOW!

[mbaird]

What started out as a 46rh transplant in my68 Fastback quickly morphed into a big rabbit hole !
While the engine was out I wanted to replace the leaky main seal . Then I remembered I had a set of Scat forged pistons for a 408 so of course I ordered a 4” Scat crank and rods . What the hell ? Right ?
The 46rh required a new driveshaft with 1350 ujoints and of course you can’t run an OD without swapping the 2.76s with a 3.55 suregrip chunk …. That may change to 3.91s because I am turning about 1800 rpm @ 55 mph now and will have to go to larger tires to keep from smoking my 205/70-14s at every stop.
The only change from my 5.9 was the rotating assembly. Holy mother of god this thing has torque ! It will annihilate those tires with 1/4 throttle ! I have a set of 15x7 steelies that will get some 225/65-15 next spring .

 

[mopowers]

What started out as a 46rh transplant in my68 Fastback quickly morphed into a big rabbit hole !
While the engine was out I wanted to replace the leaky main seal . Then I remembered I had a set of Scat forged pistons for a 408 so of course I ordered a 4” Scat crank and rods . What the hell ? Right ?
The 46rh required a new driveshaft with 1350 ujoints and of course you can’t run an OD without swapping the 2.76s with a 3.55 suregrip chunk …. That may change to 3.91s because I am turning about 1800 rpm @ 55 mph now and will have to go to larger tires to keep from smoking my 205/70-14s at every stop.
The only change from my 5.9 was the rotating assembly. Holy mother of god this thing has torque ! It will annihilate those tires with 1/4 throttle ! I have a set of 15x7 steelies that will get some 225/65-15 next spring .

What's the 408 combo? What all did you do to the 46RH? I'm planning on a 46RH build to go behind a 408 as well. What converter are you running?

 

[mbaird]

*5.9 magnum block
*IMM ported EQs
*221/229 .550 lift on a 112 Oregon Cams regrind with 1.7 Harland Sharp rockers
*Dougs 453 headers and 2.5” exhaust out to tips .
*Airgap RPM intake
* Edelbrock 1913 AVS2 800 carb
Mopar electronic ignition with Orange box

Stock lockup converter rebuilt to 2300ish stall
Trany has all the Sonax parts I could throw at it and a Transgo TFOD shift kit . Actually the trany shop didn’t use all the Sonax parts because they said it would not play well with the Transgo kit …. Pretty much a deisel trany . We will see….

Pretty simple combo

 

[mbaird]

The mild build in the Barracuda feels much faster than the W2 solid roller 408 in my 69 340 4sp Swinger . Im sure that due to the low end torque but the Swingers engine dynoed at 498 ft-lbs @ 3800 rpm . I just never spin it up to 6500 on the street and haven’t made it to the track yet . Both cars running 3.55s currently.
I will put the Cudas Drag radials on Sunday and see how it performs.

 

[mpgmike]

I keep scrolling up and down, again and again, but I can't seem to find the pictures?

 

[mopowers]

I keep scrolling up and down, again and again, but I can't seem to find the pictures?

^^^^ THIS!!

 

[mbaird]

Photos

 

[67/6barracuda]

*5.9 magnum block
*IMM ported EQs
*221/229 .550 lift on a 112 Oregon Cams regrind with 1.7 Harland Sharp rockers
*Dougs 453 headers and 2.5” exhaust out to tips .
*Airgap RPM intake
* Edelbrock 1913 AVS2 800 carb
Mopar electronic ignition with Orange box

Stock lockup converter rebuilt to 2300ish stall
Trany has all the Sonax parts I could throw at it and a Transgo TFOD shift kit . Actually the trany shop didn’t use all the Sonax parts because they said it would not play well with the Transgo kit …. Pretty much a deisel trany . We will see….

Pretty simple combo

I have parts to do a similar combo. 46rh with a pre-magnum 91 roller block scat 4” crank, scat rods and some MP cast stroker pistons, speedmaster heads, cam is .580 on a 113LSA not ideal cam but I’ll run it and see what happens when the time comes.

 

[mbaird]

Plugs still look lean . And timing still too advanced .

 

[mbaird]

I built a control box for the OD/LU using a line pressure switch. Vacuum switch and 2 delay timers . It was a copy of another members unit .
I set the timers at 7 secs for the OD and 10 for the LU . I used a 42 line pressure switch and set the vacuum switch to 7” .
I used a stock flasher switch to power up the system and OD lamp.
So once I turn the flasher switch on the system powers up when the trany line pressure hits 42 psi … thens the OD kicks in 7 seconds later and the LU 3 seconds after that. Then if I punch it both the OD and LU disengage. But the system is staying engaged when I let my foot off the throttle and I have to turn it off manually. I suspect both the line pressure and vacuum are staying above the set parameters on decel and I will have to readjust the settings . I might tee into the line pressure switch and install a pressure gauge so I can see what’s happening.

 

[mbaird]

I have parts to do a similar combo. 46rh with a pre-magnum 91 roller block scat 4” crank, scat rods and some MP cast stroker pistons, speedmaster heads, cam is .580 on a 113LSA not ideal cam but I’ll run it and see what happens when the time comes.

That should make a potent combo !

 

[mbaird]

OD kicks in around 50 mph BTW