727 or 545RFE?

[Chryco69]

I am putting a 5.7 Hemi in my 69 Bee. Should I use the factory trans attached to the 5.7 or use a small block 727? If I use thr 5.7 trans do I have to cut up the floor pan to make it fit?

 

[Lefty71]

May seem like odd advice.... but I would talk to John Cope directly about transmission selection for your swap.

CRT | The Leader in Mopar Transmissions, valve bodies, and parts (coperacingtrans.com)

HTH, Lefty71

 

[Sixpactogo]

I used the 545RFE in my 68 Charger because I wanted the extra gears for both mileage and performance. The first two gears in the 545RFE are lower than 1st gear in the 727 plus since 3rd gear is the 1:1 gear both 4th and 5th are an overdrive so to speak. My 6.1 delivers over 20mpg with the 3.23 gear and run a high 12 second quarter mile so that makes it well worth the trouble of cutting the hump. You will have to widen the hump and raise the hump both directions about 2". Also you will have to cut out the center cross member to raise it and widen it in the center area. It is major surgery so that has to be taken into consideration. The transmission cross member will need to be modified as well. New driveshaft. Here are some pics so you can get an idea of what it will take.

 

[66Satellite47]

It's looks like a very interesting change. However sure looks like an awful lot of mods required. A 727 is pretty simple. But I'm not any expert.

 

[493 Mike]

I had to cut up my new restoration floorpan to set the engine back and replace the entire tunnel but, this was to install the VG OD. Similar to what you need though. I Stole a tire off my lawn mower to push the steel into the opening and note my $26,000 counterweight.
Mike

 

[Sixpactogo]

It's looks like a very interesting change. However sure looks like an awful lot of mods required. A 727 is pretty simple. But I'm not any expert.

Yup.....Like I said, Major Surgery. Not for the faint of heart. Upgrading to the 5.7 has another list of mods required. More than once during my build, I wondered if I made the right decision but I am happy I stuck with it.

 

[furious70]

I'd use a nag1, though it sounds like you already have the truck trans

 

[quackhead96]

I am about to do the same swap in a 69 coronet 5.7 and 545RFE. In another post I thought I had read that you can move the engine forward 3" and do away with cutting the tunnel. I have not started on mine at all but its an original car with solid floors id rather not cut up but I got a good deal on a low mile engine trans and wiring harness.

 

[furious70]

The 5.7 is lighter than a big block but I'd be interested in the weight distribution if you moved it all forward 3"

 

[Sixpactogo]

I am about to do the same swap in a 69 coronet 5.7 and 545RFE. In another post I thought I had read that you can move the engine forward 3" and do away with cutting the tunnel. I have not started on mine at all but its an original car with solid floors id rather not cut up but I got a good deal on a low mile engine trans and wiring harness.

I have heard a rumor of sorts myself. 3" is a long way so it sounds a little iffy to me. More than likely cause more issues than it's worth with weight distribution, fan and header clearance issues. Maybe they used the NAG 1 transmission too since it is smaller and shorter than the 545RFE. I like the way mine looks and the position it's in so glad I did what I did. No one notices the console being higher than stock.
There were too many problems with making the NAG1 work when I did mine but the technology is there now. The NAG is a better transmission than the truck unit but I have not had issues with mine and I don't pound on it too bad. The Nag has better gear ratios and I would like 4th gear to be the 1:1 ratio instead of 3rd on the 545RFE. I hear ya on cutting a good floor. I stared at mine for quite some time before firing up the blade but mine was already in need of new metal. I guess it is not the end of the world though since it could still be put back to factory specs if a guy wanted. I'm happy with it so it won't be on my watch. The purists cry wolf but I've had way more attaboys than complainers.

 

[70chall440]

I do not know for certain but I highly doubt that the engine can be moved 3" forward and avoid modifying the trans tunnel. Use a A518 off a 2WD 96-03 Ram, its a 727 with OD.

 

[JG71B]

An older relative has a bone stock 2012 5.7 with a 518 push button OD out of a Dakota and tweaked valve body he did all himself. 8 3/4 3.23 sg. He ran his fastest time with it last week at 11.9, right there with his 2019 Challenger. AND he gets 20mpg...

 

[5.7 hemi]

The 545rfe is a decent trans. I had in my Polara 500 and used 3:91’s out back. I got 19mpg, and could bounce the rev limiter. Plus, you can use the factory flier shifter to shift the trans if ya want. But tunnel surgery is needed, and don’t move the engine forward, you will create radiator/fan problems and your going wrong way.

 

[70chall440]

An older relative has a bone stock 2012 5.7 with a 518 push button OD out of a Dakota and tweaked valve body he did all himself. 8 3/4 3.23 sg. He ran his fastest time with it last week at 11.9, right there with his 2019 Challenger. AND he gets 20mpg...

View attachment 1178465 View attachment 1178469 View attachment 1178470

I am a little confused by the oval air cleaner, it appears to be sitting on top of the stock 5.7 intake or am I not seeing this correctly? Not criticizing it, just wondering (looks pretty awesome actually)

 

[JG71B]

I am a little confused by the oval air cleaner, it appears to be sitting on top of the stock 5.7 intake or am I not seeing this correctly? Not criticizing it, just wondering (looks pretty awesome actually)

It is and you are sir! I'm certain it is more asthetic than functional considering his cold air intake. In person it looks like it was built that way. Everything fitted, nothing hillbillied. He makes fun of me and my dinosaur motor and wonders when I'm coming to the dark side lol

 

[70chall440]

It is and you are sir! I'm certain it is more asthetic than functional considering his cold air intake. In person it looks like it was built that way. Everything fitted, nothing hillbillied. He makes fun of me and my dinosaur motor and wonders when I'm coming to the dark side lol

Thats pretty awesome. I am putting a 5.7 into my 71 Charger and I might have to steal that idea.

 

[JG71B]

Thats pretty awesome. I am putting a 5.7 into my 71 Charger and I might have to steal that idea.

I had one for mine last winter but, still too pricey as I was in the middle of body and paint. Think I'll start planning now that I'm past that for the most part

 

[70chall440]

If you talk to the guy with the car, I'd be interested to know what base/lid he used.

 

[JG71B]

If you talk to the guy with the car, I'd be interested to know what base/lid he used.

It's a relative 5min down the street. I'll buzz him tomorrow night after I get one of these fenders sprayed

 

[392heminut]

Use a A518 off a 2WD 96-03 Ram, its a 727 with OD.

This is what I would recommend also. I put a TF727 in my Cuda when I did the swap back in 2009 and have been running it ever since. It's been a trouble free setup, but I want to upgrade to an A518 myself.