Author Topic: 6.1L Hemi and Automatic OD conversion help  (Read 2531 times)

Offline 71_340Challenger

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6.1L Hemi and Automatic OD conversion help
« on: June 07, 2011 - 02:12:14 am »
First, some background. I am in the process of resto-moding my 71 Challenger. I decided about a year ago that I wanted to put a late model hemi and automatic OD transmission in my 71 Challlenger that was originally a 340/727 column shift automatic car. I did a bunch of research and the prevailing response from those that had supposedly done it was to use a 45RFE or 545RFE from a 4x2 Ram truck. I purchased a 6.1L Hemi out of a wrecked 2005 Magnum and a 545RFE out of a 2002 Ram 1500. A couple of weeks ago, I was to the point in the body work that I wanted to fit the engine and trans in the car for the first time so I could figure out what needed to be done to the firewall. These same companies that were answering questions when I was researching "kit" are now no longer responding to emails and rarely returning phone calls. So, I am on my own more or less to figure this out. As a note, I am using the stock, SB k-member with a stock fast-ratio power steering box and stock torsion bar setup.

Now my questions:
1) Has anyone actually installed one of these (or seen one installed) in an ebody? I am looking for input/pictures as to the tunnel modificaitons required. It is obvious after fighting with it for a few weeks that pretty extensive modificaitons are going to be required to make the 545RFE fit. I just hate to cut up my floor a ton since it is in very good shape and no rust.
2) If I do the mods to the tunnel, I will also have to modify the rear torsion bar cross-brace as the 545RFE is too wide as the brace follows the tunnel. Any recommendations on how to modify this and not loose the strength? I have had a couple ideas, but would like some feedback on what has worked for others.
3) If I give up on the 545RFE, there are only a few other options I have found. Does anyone have any experience comments on pros/cons of each?
        a) gear vendors unit (~$2700) + cost to rebuild my original 727
        b) a518 automatic (not sure)
        c) Keisler 4L60E conversion ($4900)
        d) convert to 5-speed manaul (~$5700 from Keisler) - I would love this option, but the almost $6k cost is a killer right now.

I need to limit the damage as I already purchased a package, including wiring and transmission controller to run the 545RFE. I know that people on this board are sure to have some experience or know someone who does that can shed some light on the best path forward.

I think I am going to have to end up startingt a thread to cover this conversion as nothing has going as smoothly as it seems like it should considering I am not the first to do this conversion. Thanks.
1971 Dodge Challenger                
2009 Dodge Challenger R/T, 6 speed manual
2009 Dodge Charger R/T w/ Road & Track Package
1995 Ford F-150

Offline 360FISH

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Re: 6.1L Hemi and Automatic OD conversion help
« Reply #1 on: June 11, 2011 - 12:55:38 am »
I'm no expert... I've been looking at all the same options... 
Here is a good thread on the A518.

I'm looking at automatics too... 
I've heard that th 700r4 fits well, but I can't find good detail on it.  This would be a low cost option with OD and no tunnel mods...
lots of other options but not a  lot of good material to research.

I'd love to hear what you end up doing.
« Last Edit: June 26, 2011 - 01:49:53 pm by 360FISH »
1973 Cuda   Semi-Pro Touring
360 SB - 518/OD auto tranny - FAST EZ EFI - Edelbrock Fuel sump - HHR fan
Hella H4 headlights on relays - 97 Dodge Avenger seats - Chin spoiler - Bumpers pulled in to 72 offset


Offline autodynamics

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Re: 6.1L Hemi and Automatic OD conversion help
« Reply #2 on: July 05, 2011 - 04:03:08 am »
Keisler auto is a perfect cutting reliable and strong I have one behind My 6.1 for 11k

Offline ragtopdodge

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Re: 6.1L Hemi and Automatic OD conversion help
« Reply #3 on: July 14, 2011 - 07:41:18 pm »
These guys might've been able to fit a 545RE in our cars:


someone there might've done this swap.
'70 318-auto Chally 'vert
'71 383-auto 'Cuda 'vert (sold)
06 300c SRT8
04 2500 QCLB 4x4 HO